From c75d8e96f377b59b887a81b31adb00dd1957c3c8 Mon Sep 17 00:00:00 2001 From: Colin Ian King Date: Wed, 20 Jan 2016 11:13:46 +0000 Subject: IMA: fix non-ANSI declaration of ima_check_policy() ima_check_policy() has no parameters, so use the normal void parameter convention to make it match the prototype in the header file security/integrity/ima/ima.h Signed-off-by: Colin Ian King Signed-off-by: Mimi Zohar --- security/integrity/ima/ima_policy.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'security') diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 0a3b781f18e5..e0e18cc5930a 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -417,7 +417,7 @@ void __init ima_init_policy(void) } /* Make sure we have a valid policy, at least containing some rules. */ -int ima_check_policy() +int ima_check_policy(void) { if (list_empty(&ima_temp_rules)) return -EINVAL; -- cgit v1.2.3 From 1525b06d99b117198ea8d6c128ee5bf28ceb6723 Mon Sep 17 00:00:00 2001 From: Dmitry Kasatkin Date: Thu, 30 Oct 2014 12:39:39 +0200 Subject: ima: separate 'security.ima' reading functionality from collect Instead of passing pointers to pointers to ima_collect_measurent() to read and return the 'security.ima' xattr value, this patch moves the functionality to the calling process_measurement() to directly read the xattr and pass only the hash algo to the ima_collect_measurement(). Signed-off-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar --- security/integrity/ima/ima.h | 15 +++++++-------- security/integrity/ima/ima_api.c | 15 +++------------ security/integrity/ima/ima_appraise.c | 25 ++++++++++++++----------- security/integrity/ima/ima_crypto.c | 2 +- security/integrity/ima/ima_init.c | 2 +- security/integrity/ima/ima_main.c | 11 +++++++---- security/integrity/ima/ima_template.c | 2 -- security/integrity/ima/ima_template_lib.c | 1 - 8 files changed, 33 insertions(+), 40 deletions(-) (limited to 'security') diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index 585af61ed399..fb8da36b1d86 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -23,6 +23,7 @@ #include #include #include +#include #include "../integrity.h" @@ -140,9 +141,7 @@ static inline unsigned long ima_hash_key(u8 *digest) int ima_get_action(struct inode *inode, int mask, int function); int ima_must_measure(struct inode *inode, int mask, int function); int ima_collect_measurement(struct integrity_iint_cache *iint, - struct file *file, - struct evm_ima_xattr_data **xattr_value, - int *xattr_len); + struct file *file, enum hash_algo algo); void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file, const unsigned char *filename, struct evm_ima_xattr_data *xattr_value, @@ -188,8 +187,8 @@ int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func); void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file); enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint, int func); -void ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int xattr_len, - struct ima_digest_data *hash); +enum hash_algo ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, + int xattr_len); int ima_read_xattr(struct dentry *dentry, struct evm_ima_xattr_data **xattr_value); @@ -221,10 +220,10 @@ static inline enum integrity_status ima_get_cache_status(struct integrity_iint_c return INTEGRITY_UNKNOWN; } -static inline void ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, - int xattr_len, - struct ima_digest_data *hash) +static inline enum hash_algo +ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int xattr_len) { + return ima_hash_algo; } static inline int ima_read_xattr(struct dentry *dentry, diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c index 1d950fbb2aec..e7c7a5d41413 100644 --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -18,7 +18,7 @@ #include #include #include -#include + #include "ima.h" /* @@ -188,9 +188,7 @@ int ima_get_action(struct inode *inode, int mask, int function) * Return 0 on success, error code otherwise */ int ima_collect_measurement(struct integrity_iint_cache *iint, - struct file *file, - struct evm_ima_xattr_data **xattr_value, - int *xattr_len) + struct file *file, enum hash_algo algo) { const char *audit_cause = "failed"; struct inode *inode = file_inode(file); @@ -201,9 +199,6 @@ int ima_collect_measurement(struct integrity_iint_cache *iint, char digest[IMA_MAX_DIGEST_SIZE]; } hash; - if (xattr_value) - *xattr_len = ima_read_xattr(file->f_path.dentry, xattr_value); - if (!(iint->flags & IMA_COLLECTED)) { u64 i_version = file_inode(file)->i_version; @@ -213,11 +208,7 @@ int ima_collect_measurement(struct integrity_iint_cache *iint, goto out; } - /* use default hash algorithm */ - hash.hdr.algo = ima_hash_algo; - - if (xattr_value) - ima_get_hash_algo(*xattr_value, *xattr_len, &hash.hdr); + hash.hdr.algo = algo; result = ima_calc_file_hash(file, &hash.hdr); if (!result) { diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index 1873b5536f80..9c2b46b90be8 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -15,7 +15,6 @@ #include #include #include -#include #include "ima.h" @@ -130,36 +129,40 @@ static void ima_cache_flags(struct integrity_iint_cache *iint, int func) } } -void ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int xattr_len, - struct ima_digest_data *hash) +enum hash_algo ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, + int xattr_len) { struct signature_v2_hdr *sig; if (!xattr_value || xattr_len < 2) - return; + /* return default hash algo */ + return ima_hash_algo; switch (xattr_value->type) { case EVM_IMA_XATTR_DIGSIG: sig = (typeof(sig))xattr_value; if (sig->version != 2 || xattr_len <= sizeof(*sig)) - return; - hash->algo = sig->hash_algo; + return ima_hash_algo; + return sig->hash_algo; break; case IMA_XATTR_DIGEST_NG: - hash->algo = xattr_value->digest[0]; + return xattr_value->digest[0]; break; case IMA_XATTR_DIGEST: /* this is for backward compatibility */ if (xattr_len == 21) { unsigned int zero = 0; if (!memcmp(&xattr_value->digest[16], &zero, 4)) - hash->algo = HASH_ALGO_MD5; + return HASH_ALGO_MD5; else - hash->algo = HASH_ALGO_SHA1; + return HASH_ALGO_SHA1; } else if (xattr_len == 17) - hash->algo = HASH_ALGO_MD5; + return HASH_ALGO_MD5; break; } + + /* return default hash algo */ + return ima_hash_algo; } int ima_read_xattr(struct dentry *dentry, @@ -296,7 +299,7 @@ void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file) if (iint->flags & IMA_DIGSIG) return; - rc = ima_collect_measurement(iint, file, NULL, NULL); + rc = ima_collect_measurement(iint, file, ima_hash_algo); if (rc < 0) return; diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c index 6eb62936c672..fb30ce406af4 100644 --- a/security/integrity/ima/ima_crypto.c +++ b/security/integrity/ima/ima_crypto.c @@ -24,7 +24,7 @@ #include #include #include -#include + #include "ima.h" struct ahash_completion { diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c index bd79f254d204..5d679a685616 100644 --- a/security/integrity/ima/ima_init.c +++ b/security/integrity/ima/ima_init.c @@ -21,7 +21,7 @@ #include #include #include -#include + #include "ima.h" /* name for boot aggregate entry */ diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 9d96551d0196..af4c3c1700b5 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -24,7 +24,6 @@ #include #include #include -#include #include "ima.h" @@ -163,9 +162,10 @@ static int process_measurement(struct file *file, int mask, int function, char *pathbuf = NULL; const char *pathname = NULL; int rc = -ENOMEM, action, must_appraise; - struct evm_ima_xattr_data *xattr_value = NULL, **xattr_ptr = NULL; + struct evm_ima_xattr_data *xattr_value = NULL; int xattr_len = 0; bool violation_check; + enum hash_algo hash_algo; if (!ima_policy_flag || !S_ISREG(inode->i_mode)) return 0; @@ -221,9 +221,12 @@ static int process_measurement(struct file *file, int mask, int function, template_desc = ima_template_desc_current(); if ((action & IMA_APPRAISE_SUBMASK) || strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) != 0) - xattr_ptr = &xattr_value; + /* read 'security.ima' */ + xattr_len = ima_read_xattr(file->f_path.dentry, &xattr_value); - rc = ima_collect_measurement(iint, file, xattr_ptr, &xattr_len); + hash_algo = ima_get_hash_algo(xattr_value, xattr_len); + + rc = ima_collect_measurement(iint, file, hash_algo); if (rc != 0) { if (file->f_flags & O_DIRECT) rc = (iint->flags & IMA_PERMIT_DIRECTIO) ? 0 : -EACCES; diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c index 0b7404ebfa80..febd12ed9b55 100644 --- a/security/integrity/ima/ima_template.c +++ b/security/integrity/ima/ima_template.c @@ -15,8 +15,6 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt -#include - #include "ima.h" #include "ima_template_lib.h" diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c index 2934e3d377f1..f9bae04ba176 100644 --- a/security/integrity/ima/ima_template_lib.c +++ b/security/integrity/ima/ima_template_lib.c @@ -12,7 +12,6 @@ * File: ima_template_lib.c * Library of supported template fields. */ -#include #include "ima_template_lib.h" -- cgit v1.2.3 From b5269ab3e29b17e3419c65986bcc1b54b798acc2 Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Thu, 28 Jan 2016 13:10:36 -0500 Subject: ima: refactor ima_policy_show() to display "ima_hooks" rules Define and call a function to display the "ima_hooks" rules. Signed-off-by: Mimi Zohar Acked-by: Petko Manolov Acked-by: Dmitry Kasatkin --- security/integrity/ima/ima_policy.c | 63 +++++++++++++++++++++---------------- 1 file changed, 36 insertions(+), 27 deletions(-) (limited to 'security') diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index e0e18cc5930a..43b642557d6c 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -903,6 +903,40 @@ void ima_policy_stop(struct seq_file *m, void *v) #define mt(token) mask_tokens[token] #define ft(token) func_tokens[token] +/* + * policy_func_show - display the ima_hooks policy rule + */ +static void policy_func_show(struct seq_file *m, enum ima_hooks func) +{ + char tbuf[64] = {0,}; + + switch (func) { + case FILE_CHECK: + seq_printf(m, pt(Opt_func), ft(func_file)); + break; + case MMAP_CHECK: + seq_printf(m, pt(Opt_func), ft(func_mmap)); + break; + case BPRM_CHECK: + seq_printf(m, pt(Opt_func), ft(func_bprm)); + break; + case MODULE_CHECK: + seq_printf(m, pt(Opt_func), ft(func_module)); + break; + case FIRMWARE_CHECK: + seq_printf(m, pt(Opt_func), ft(func_firmware)); + break; + case POST_SETATTR: + seq_printf(m, pt(Opt_func), ft(func_post)); + break; + default: + snprintf(tbuf, sizeof(tbuf), "%d", func); + seq_printf(m, pt(Opt_func), tbuf); + break; + } + seq_puts(m, " "); +} + int ima_policy_show(struct seq_file *m, void *v) { struct ima_rule_entry *entry = v; @@ -924,33 +958,8 @@ int ima_policy_show(struct seq_file *m, void *v) seq_puts(m, " "); - if (entry->flags & IMA_FUNC) { - switch (entry->func) { - case FILE_CHECK: - seq_printf(m, pt(Opt_func), ft(func_file)); - break; - case MMAP_CHECK: - seq_printf(m, pt(Opt_func), ft(func_mmap)); - break; - case BPRM_CHECK: - seq_printf(m, pt(Opt_func), ft(func_bprm)); - break; - case MODULE_CHECK: - seq_printf(m, pt(Opt_func), ft(func_module)); - break; - case FIRMWARE_CHECK: - seq_printf(m, pt(Opt_func), ft(func_firmware)); - break; - case POST_SETATTR: - seq_printf(m, pt(Opt_func), ft(func_post)); - break; - default: - snprintf(tbuf, sizeof(tbuf), "%d", entry->func); - seq_printf(m, pt(Opt_func), tbuf); - break; - } - seq_puts(m, " "); - } + if (entry->flags & IMA_FUNC) + policy_func_show(m, entry->func); if (entry->flags & IMA_MASK) { if (entry->mask & MAY_EXEC) -- cgit v1.2.3 From 4ad87a3d7444de08858e9dc8014e948670945b6c Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Thu, 14 Jan 2016 20:59:14 -0500 Subject: ima: use "ima_hooks" enum as function argument Cleanup the function arguments by using "ima_hooks" enumerator as needed. Signed-off-by: Mimi Zohar Acked-by: Petko Manolov Acked-by: Dmitry Kasatkin --- security/integrity/ima/ima.h | 25 +++++++++++++++++-------- security/integrity/ima/ima_api.c | 6 +++--- security/integrity/ima/ima_appraise.c | 13 +++++++------ security/integrity/ima/ima_main.c | 14 +++++++------- security/integrity/ima/ima_policy.c | 6 +++--- 5 files changed, 37 insertions(+), 27 deletions(-) (limited to 'security') diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index fb8da36b1d86..b7e793501bdb 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -137,9 +137,18 @@ static inline unsigned long ima_hash_key(u8 *digest) return hash_long(*digest, IMA_HASH_BITS); } +enum ima_hooks { + FILE_CHECK = 1, + MMAP_CHECK, + BPRM_CHECK, + MODULE_CHECK, + FIRMWARE_CHECK, + POST_SETATTR +}; + /* LIM API function definitions */ -int ima_get_action(struct inode *inode, int mask, int function); -int ima_must_measure(struct inode *inode, int mask, int function); +int ima_get_action(struct inode *inode, int mask, enum ima_hooks func); +int ima_must_measure(struct inode *inode, int mask, enum ima_hooks func); int ima_collect_measurement(struct integrity_iint_cache *iint, struct file *file, enum hash_algo algo); void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file, @@ -156,8 +165,6 @@ void ima_free_template_entry(struct ima_template_entry *entry); const char *ima_d_path(struct path *path, char **pathbuf); /* IMA policy related functions */ -enum ima_hooks { FILE_CHECK = 1, MMAP_CHECK, BPRM_CHECK, MODULE_CHECK, FIRMWARE_CHECK, POST_SETATTR }; - int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask, int flags); void ima_init_policy(void); @@ -179,21 +186,22 @@ int ima_policy_show(struct seq_file *m, void *v); #define IMA_APPRAISE_FIRMWARE 0x10 #ifdef CONFIG_IMA_APPRAISE -int ima_appraise_measurement(int func, struct integrity_iint_cache *iint, +int ima_appraise_measurement(enum ima_hooks func, + struct integrity_iint_cache *iint, struct file *file, const unsigned char *filename, struct evm_ima_xattr_data *xattr_value, int xattr_len, int opened); int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func); void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file); enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint, - int func); + enum ima_hooks func); enum hash_algo ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int xattr_len); int ima_read_xattr(struct dentry *dentry, struct evm_ima_xattr_data **xattr_value); #else -static inline int ima_appraise_measurement(int func, +static inline int ima_appraise_measurement(enum ima_hooks func, struct integrity_iint_cache *iint, struct file *file, const unsigned char *filename, @@ -215,7 +223,8 @@ static inline void ima_update_xattr(struct integrity_iint_cache *iint, } static inline enum integrity_status ima_get_cache_status(struct integrity_iint_cache - *iint, int func) + *iint, + enum ima_hooks func) { return INTEGRITY_UNKNOWN; } diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c index e7c7a5d41413..8750254506a9 100644 --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -156,7 +156,7 @@ err_out: * ima_get_action - appraise & measure decision based on policy. * @inode: pointer to inode to measure * @mask: contains the permission mask (MAY_READ, MAY_WRITE, MAY_EXECUTE) - * @function: calling function (FILE_CHECK, BPRM_CHECK, MMAP_CHECK, MODULE_CHECK) + * @func: caller identifier * * The policy is defined in terms of keypairs: * subj=, obj=, type=, func=, mask=, fsmagic= @@ -168,13 +168,13 @@ err_out: * Returns IMA_MEASURE, IMA_APPRAISE mask. * */ -int ima_get_action(struct inode *inode, int mask, int function) +int ima_get_action(struct inode *inode, int mask, enum ima_hooks func) { int flags = IMA_MEASURE | IMA_AUDIT | IMA_APPRAISE; flags &= ima_policy_flag; - return ima_match_policy(inode, function, mask, flags); + return ima_match_policy(inode, func, mask, flags); } /* diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index 9c2b46b90be8..288844908788 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -67,7 +67,7 @@ static int ima_fix_xattr(struct dentry *dentry, /* Return specific func appraised cached result */ enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint, - int func) + enum ima_hooks func) { switch (func) { case MMAP_CHECK: @@ -85,7 +85,8 @@ enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint, } static void ima_set_cache_status(struct integrity_iint_cache *iint, - int func, enum integrity_status status) + enum ima_hooks func, + enum integrity_status status) { switch (func) { case MMAP_CHECK: @@ -103,11 +104,11 @@ static void ima_set_cache_status(struct integrity_iint_cache *iint, case FILE_CHECK: default: iint->ima_file_status = status; - break; } } -static void ima_cache_flags(struct integrity_iint_cache *iint, int func) +static void ima_cache_flags(struct integrity_iint_cache *iint, + enum ima_hooks func) { switch (func) { case MMAP_CHECK: @@ -125,7 +126,6 @@ static void ima_cache_flags(struct integrity_iint_cache *iint, int func) case FILE_CHECK: default: iint->flags |= (IMA_FILE_APPRAISED | IMA_APPRAISED); - break; } } @@ -185,7 +185,8 @@ int ima_read_xattr(struct dentry *dentry, * * Return 0 on success, error code otherwise */ -int ima_appraise_measurement(int func, struct integrity_iint_cache *iint, +int ima_appraise_measurement(enum ima_hooks func, + struct integrity_iint_cache *iint, struct file *file, const unsigned char *filename, struct evm_ima_xattr_data *xattr_value, int xattr_len, int opened) diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index af4c3c1700b5..1be99a27a7f3 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -153,8 +153,8 @@ void ima_file_free(struct file *file) ima_check_last_writer(iint, inode, file); } -static int process_measurement(struct file *file, int mask, int function, - int opened) +static int process_measurement(struct file *file, int mask, + enum ima_hooks func, int opened) { struct inode *inode = file_inode(file); struct integrity_iint_cache *iint = NULL; @@ -174,8 +174,8 @@ static int process_measurement(struct file *file, int mask, int function, * bitmask based on the appraise/audit/measurement policy. * Included is the appraise submask. */ - action = ima_get_action(inode, mask, function); - violation_check = ((function == FILE_CHECK || function == MMAP_CHECK) && + action = ima_get_action(inode, mask, func); + violation_check = ((func == FILE_CHECK || func == MMAP_CHECK) && (ima_policy_flag & IMA_MEASURE)); if (!action && !violation_check) return 0; @@ -184,7 +184,7 @@ static int process_measurement(struct file *file, int mask, int function, /* Is the appraise rule hook specific? */ if (action & IMA_FILE_APPRAISE) - function = FILE_CHECK; + func = FILE_CHECK; inode_lock(inode); @@ -214,7 +214,7 @@ static int process_measurement(struct file *file, int mask, int function, /* Nothing to do, just return existing appraised status */ if (!action) { if (must_appraise) - rc = ima_get_cache_status(iint, function); + rc = ima_get_cache_status(iint, func); goto out_digsig; } @@ -240,7 +240,7 @@ static int process_measurement(struct file *file, int mask, int function, ima_store_measurement(iint, file, pathname, xattr_value, xattr_len); if (action & IMA_APPRAISE_SUBMASK) - rc = ima_appraise_measurement(function, iint, file, pathname, + rc = ima_appraise_measurement(func, iint, file, pathname, xattr_value, xattr_len, opened); if (action & IMA_AUDIT) ima_audit_measurement(iint, pathname); diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 43b642557d6c..b089ebef6648 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -207,8 +207,8 @@ static void ima_lsm_update_rules(void) * * Returns true on rule match, false on failure. */ -static bool ima_match_rules(struct ima_rule_entry *rule, - struct inode *inode, enum ima_hooks func, int mask) +static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode, + enum ima_hooks func, int mask) { struct task_struct *tsk = current; const struct cred *cred = current_cred(); @@ -289,7 +289,7 @@ retry: * In addition to knowing that we need to appraise the file in general, * we need to differentiate between calling hooks, for hook specific rules. */ -static int get_subaction(struct ima_rule_entry *rule, int func) +static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func) { if (!(rule->flags & IMA_FUNC)) return IMA_FILE_APPRAISE; -- cgit v1.2.3 From b44a7dfc6fa16e01f2497c9fa62c3926f94be174 Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Mon, 28 Dec 2015 16:02:29 -0500 Subject: vfs: define a generic function to read a file from the kernel For a while it was looked down upon to directly read files from Linux. These days there exists a few mechanisms in the kernel that do just this though to load a file into a local buffer. There are minor but important checks differences on each. This patch set is the first attempt at resolving some of these differences. This patch introduces a common function for reading files from the kernel with the corresponding security post-read hook and function. Changelog v4+: - export security_kernel_post_read_file() - Fengguang Wu v3: - additional bounds checking - Luis v2: - To simplify patch review, re-ordered patches Signed-off-by: Mimi Zohar Reviewed-by: Luis R. Rodriguez Acked-by: Kees Cook Cc: Al Viro --- fs/exec.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++ include/linux/fs.h | 1 + include/linux/lsm_hooks.h | 9 ++++++++ include/linux/security.h | 7 +++++++ security/security.c | 8 +++++++ 5 files changed, 78 insertions(+) (limited to 'security') diff --git a/fs/exec.c b/fs/exec.c index dcd4ac7d3f1e..6b6668baa44a 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -56,6 +56,7 @@ #include #include #include +#include #include #include @@ -831,6 +832,58 @@ int kernel_read(struct file *file, loff_t offset, EXPORT_SYMBOL(kernel_read); +int kernel_read_file(struct file *file, void **buf, loff_t *size, + loff_t max_size) +{ + loff_t i_size, pos; + ssize_t bytes = 0; + int ret; + + if (!S_ISREG(file_inode(file)->i_mode) || max_size < 0) + return -EINVAL; + + i_size = i_size_read(file_inode(file)); + if (max_size > 0 && i_size > max_size) + return -EFBIG; + if (i_size <= 0) + return -EINVAL; + + *buf = vmalloc(i_size); + if (!*buf) + return -ENOMEM; + + pos = 0; + while (pos < i_size) { + bytes = kernel_read(file, pos, (char *)(*buf) + pos, + i_size - pos); + if (bytes < 0) { + ret = bytes; + goto out; + } + + if (bytes == 0) + break; + pos += bytes; + } + + if (pos != i_size) { + ret = -EIO; + goto out; + } + + ret = security_kernel_post_read_file(file, *buf, i_size); + if (!ret) + *size = pos; + +out: + if (ret < 0) { + vfree(*buf); + *buf = NULL; + } + return ret; +} +EXPORT_SYMBOL_GPL(kernel_read_file); + ssize_t read_code(struct file *file, unsigned long addr, loff_t pos, size_t len) { ssize_t res = vfs_read(file, (void __user *)addr, len, &pos); diff --git a/include/linux/fs.h b/include/linux/fs.h index ae681002100a..9a83d82b61ac 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2577,6 +2577,7 @@ static inline void i_readcount_inc(struct inode *inode) extern int do_pipe_flags(int *, int); extern int kernel_read(struct file *, loff_t, char *, unsigned long); +extern int kernel_read_file(struct file *, void **, loff_t *, loff_t); extern ssize_t kernel_write(struct file *, const char *, size_t, loff_t); extern ssize_t __kernel_write(struct file *, const char *, size_t, loff_t *); extern struct file * open_exec(const char *); diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 71969de4058c..f82631cc7248 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -561,6 +561,13 @@ * the kernel module to load. If the module is being loaded from a blob, * this argument will be NULL. * Return 0 if permission is granted. + * @kernel_post_read_file: + * Read a file specified by userspace. + * @file contains the file structure pointing to the file being read + * by the kernel. + * @buf pointer to buffer containing the file contents. + * @size length of the file contents. + * Return 0 if permission is granted. * @task_fix_setuid: * Update the module's state after setting one or more of the user * identity attributes of the current process. The @flags parameter @@ -1457,6 +1464,7 @@ union security_list_options { int (*kernel_fw_from_file)(struct file *file, char *buf, size_t size); int (*kernel_module_request)(char *kmod_name); int (*kernel_module_from_file)(struct file *file); + int (*kernel_post_read_file)(struct file *file, char *buf, loff_t size); int (*task_fix_setuid)(struct cred *new, const struct cred *old, int flags); int (*task_setpgid)(struct task_struct *p, pid_t pgid); @@ -1716,6 +1724,7 @@ struct security_hook_heads { struct list_head kernel_act_as; struct list_head kernel_create_files_as; struct list_head kernel_fw_from_file; + struct list_head kernel_post_read_file; struct list_head kernel_module_request; struct list_head kernel_module_from_file; struct list_head task_fix_setuid; diff --git a/include/linux/security.h b/include/linux/security.h index 4824a4ccaf1c..f30f5647d1e1 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -301,6 +301,7 @@ int security_kernel_create_files_as(struct cred *new, struct inode *inode); int security_kernel_fw_from_file(struct file *file, char *buf, size_t size); int security_kernel_module_request(char *kmod_name); int security_kernel_module_from_file(struct file *file); +int security_kernel_post_read_file(struct file *file, char *buf, loff_t size); int security_task_fix_setuid(struct cred *new, const struct cred *old, int flags); int security_task_setpgid(struct task_struct *p, pid_t pgid); @@ -866,6 +867,12 @@ static inline int security_kernel_module_from_file(struct file *file) return 0; } +static inline int security_kernel_post_read_file(struct file *file, + char *buf, loff_t size) +{ + return 0; +} + static inline int security_task_fix_setuid(struct cred *new, const struct cred *old, int flags) diff --git a/security/security.c b/security/security.c index e8ffd92ae2eb..c98dd6bf4ebd 100644 --- a/security/security.c +++ b/security/security.c @@ -910,6 +910,12 @@ int security_kernel_module_from_file(struct file *file) return ima_module_check(file); } +int security_kernel_post_read_file(struct file *file, char *buf, loff_t size) +{ + return call_int_hook(kernel_post_read_file, 0, file, buf, size); +} +EXPORT_SYMBOL_GPL(security_kernel_post_read_file); + int security_task_fix_setuid(struct cred *new, const struct cred *old, int flags) { @@ -1697,6 +1703,8 @@ struct security_hook_heads security_hook_heads = { LIST_HEAD_INIT(security_hook_heads.kernel_module_request), .kernel_module_from_file = LIST_HEAD_INIT(security_hook_heads.kernel_module_from_file), + .kernel_post_read_file = + LIST_HEAD_INIT(security_hook_heads.kernel_post_read_file), .task_fix_setuid = LIST_HEAD_INIT(security_hook_heads.task_fix_setuid), .task_setpgid = LIST_HEAD_INIT(security_hook_heads.task_setpgid), -- cgit v1.2.3 From bc8ca5b92d54f6f005fa73ad546f02fca26ddd85 Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Sun, 24 Jan 2016 10:07:32 -0500 Subject: vfs: define kernel_read_file_id enumeration To differentiate between the kernel_read_file() callers, this patch defines a new enumeration named kernel_read_file_id and includes the caller identifier as an argument. Subsequent patches define READING_KEXEC_IMAGE, READING_KEXEC_INITRAMFS, READING_FIRMWARE, READING_MODULE, and READING_POLICY. Changelog v3: - Replace the IMA specific enumeration with a generic one. Signed-off-by: Mimi Zohar Acked-by: Kees Cook Acked-by: Luis R. Rodriguez Cc: Al Viro --- fs/exec.c | 4 ++-- include/linux/fs.h | 7 ++++++- include/linux/lsm_hooks.h | 4 +++- include/linux/security.h | 7 +++++-- security/security.c | 5 +++-- 5 files changed, 19 insertions(+), 8 deletions(-) (limited to 'security') diff --git a/fs/exec.c b/fs/exec.c index 6b6668baa44a..1138dc502c77 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -833,7 +833,7 @@ int kernel_read(struct file *file, loff_t offset, EXPORT_SYMBOL(kernel_read); int kernel_read_file(struct file *file, void **buf, loff_t *size, - loff_t max_size) + loff_t max_size, enum kernel_read_file_id id) { loff_t i_size, pos; ssize_t bytes = 0; @@ -871,7 +871,7 @@ int kernel_read_file(struct file *file, void **buf, loff_t *size, goto out; } - ret = security_kernel_post_read_file(file, *buf, i_size); + ret = security_kernel_post_read_file(file, *buf, i_size, id); if (!ret) *size = pos; diff --git a/include/linux/fs.h b/include/linux/fs.h index 9a83d82b61ac..aa84bcb9c368 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2576,8 +2576,13 @@ static inline void i_readcount_inc(struct inode *inode) #endif extern int do_pipe_flags(int *, int); +enum kernel_read_file_id { + READING_MAX_ID +}; + extern int kernel_read(struct file *, loff_t, char *, unsigned long); -extern int kernel_read_file(struct file *, void **, loff_t *, loff_t); +extern int kernel_read_file(struct file *, void **, loff_t *, loff_t, + enum kernel_read_file_id); extern ssize_t kernel_write(struct file *, const char *, size_t, loff_t); extern ssize_t __kernel_write(struct file *, const char *, size_t, loff_t *); extern struct file * open_exec(const char *); diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index f82631cc7248..2337f33913c1 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -567,6 +567,7 @@ * by the kernel. * @buf pointer to buffer containing the file contents. * @size length of the file contents. + * @id kernel read file identifier * Return 0 if permission is granted. * @task_fix_setuid: * Update the module's state after setting one or more of the user @@ -1464,7 +1465,8 @@ union security_list_options { int (*kernel_fw_from_file)(struct file *file, char *buf, size_t size); int (*kernel_module_request)(char *kmod_name); int (*kernel_module_from_file)(struct file *file); - int (*kernel_post_read_file)(struct file *file, char *buf, loff_t size); + int (*kernel_post_read_file)(struct file *file, char *buf, loff_t size, + enum kernel_read_file_id id); int (*task_fix_setuid)(struct cred *new, const struct cred *old, int flags); int (*task_setpgid)(struct task_struct *p, pid_t pgid); diff --git a/include/linux/security.h b/include/linux/security.h index f30f5647d1e1..b68ce94e4e00 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -28,6 +28,7 @@ #include #include #include +#include struct linux_binprm; struct cred; @@ -301,7 +302,8 @@ int security_kernel_create_files_as(struct cred *new, struct inode *inode); int security_kernel_fw_from_file(struct file *file, char *buf, size_t size); int security_kernel_module_request(char *kmod_name); int security_kernel_module_from_file(struct file *file); -int security_kernel_post_read_file(struct file *file, char *buf, loff_t size); +int security_kernel_post_read_file(struct file *file, char *buf, loff_t size, + enum kernel_read_file_id id); int security_task_fix_setuid(struct cred *new, const struct cred *old, int flags); int security_task_setpgid(struct task_struct *p, pid_t pgid); @@ -868,7 +870,8 @@ static inline int security_kernel_module_from_file(struct file *file) } static inline int security_kernel_post_read_file(struct file *file, - char *buf, loff_t size) + char *buf, loff_t size, + enum kernel_read_file_id id) { return 0; } diff --git a/security/security.c b/security/security.c index c98dd6bf4ebd..5b96eabaafd4 100644 --- a/security/security.c +++ b/security/security.c @@ -910,9 +910,10 @@ int security_kernel_module_from_file(struct file *file) return ima_module_check(file); } -int security_kernel_post_read_file(struct file *file, char *buf, loff_t size) +int security_kernel_post_read_file(struct file *file, char *buf, loff_t size, + enum kernel_read_file_id id) { - return call_int_hook(kernel_post_read_file, 0, file, buf, size); + return call_int_hook(kernel_post_read_file, 0, file, buf, size, id); } EXPORT_SYMBOL_GPL(security_kernel_post_read_file); -- cgit v1.2.3 From 11d7646df8e800f434ff710ad6100acbea59068e Mon Sep 17 00:00:00 2001 From: Dmitry Kasatkin Date: Thu, 17 Apr 2014 12:01:40 +0300 Subject: ima: provide buffer hash calculation function This patch provides convenient buffer hash calculation function. Changelog v3: - fix while hash calculation - Dmitry v1: - rewrite to support loff_t sized buffers - Mimi (based on Fenguang Wu's testing) Signed-off-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar --- security/integrity/ima/ima.h | 2 ++ security/integrity/ima/ima_crypto.c | 47 +++++++++++++++++++++++++++++++++++++ 2 files changed, 49 insertions(+) (limited to 'security') diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index b7e793501bdb..2c5262f2823f 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -107,6 +107,8 @@ int ima_add_template_entry(struct ima_template_entry *entry, int violation, const char *op, struct inode *inode, const unsigned char *filename); int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash); +int ima_calc_buffer_hash(const void *buf, loff_t len, + struct ima_digest_data *hash); int ima_calc_field_array_hash(struct ima_field_data *field_data, struct ima_template_desc *desc, int num_fields, struct ima_digest_data *hash); diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c index fb30ce406af4..fccb6ceb388b 100644 --- a/security/integrity/ima/ima_crypto.c +++ b/security/integrity/ima/ima_crypto.c @@ -519,6 +519,53 @@ int ima_calc_field_array_hash(struct ima_field_data *field_data, return rc; } +static int calc_buffer_shash_tfm(const void *buf, loff_t size, + struct ima_digest_data *hash, + struct crypto_shash *tfm) +{ + SHASH_DESC_ON_STACK(shash, tfm); + unsigned int len; + int rc; + + shash->tfm = tfm; + shash->flags = 0; + + hash->length = crypto_shash_digestsize(tfm); + + rc = crypto_shash_init(shash); + if (rc != 0) + return rc; + + while (size) { + len = size < PAGE_SIZE ? size : PAGE_SIZE; + rc = crypto_shash_update(shash, buf, len); + if (rc) + break; + buf += len; + size -= len; + } + + if (!rc) + rc = crypto_shash_final(shash, hash->digest); + return rc; +} + +int ima_calc_buffer_hash(const void *buf, loff_t len, + struct ima_digest_data *hash) +{ + struct crypto_shash *tfm; + int rc; + + tfm = ima_alloc_tfm(hash->algo); + if (IS_ERR(tfm)) + return PTR_ERR(tfm); + + rc = calc_buffer_shash_tfm(buf, len, hash, tfm); + + ima_free_tfm(tfm); + return rc; +} + static void __init ima_pcrread(int idx, u8 *pcr) { if (!ima_used_chip) -- cgit v1.2.3 From 98304bcf71845e97c0b5c800ae619311156b66c1 Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Mon, 28 Dec 2015 11:56:09 -0500 Subject: ima: calculate the hash of a buffer using aynchronous hash(ahash) Setting up ahash has some overhead. Only use ahash to calculate the hash of a buffer, if the buffer is larger than ima_ahash_minsize. Signed-off-by: Mimi Zohar Acked-by: Dmitry Kasatkin --- security/integrity/ima/ima_crypto.c | 75 ++++++++++++++++++++++++++++++++++++- 1 file changed, 73 insertions(+), 2 deletions(-) (limited to 'security') diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c index fccb6ceb388b..38f2ed830dd6 100644 --- a/security/integrity/ima/ima_crypto.c +++ b/security/integrity/ima/ima_crypto.c @@ -519,6 +519,63 @@ int ima_calc_field_array_hash(struct ima_field_data *field_data, return rc; } +static int calc_buffer_ahash_atfm(const void *buf, loff_t len, + struct ima_digest_data *hash, + struct crypto_ahash *tfm) +{ + struct ahash_request *req; + struct scatterlist sg; + struct ahash_completion res; + int rc, ahash_rc = 0; + + hash->length = crypto_ahash_digestsize(tfm); + + req = ahash_request_alloc(tfm, GFP_KERNEL); + if (!req) + return -ENOMEM; + + init_completion(&res.completion); + ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG | + CRYPTO_TFM_REQ_MAY_SLEEP, + ahash_complete, &res); + + rc = ahash_wait(crypto_ahash_init(req), &res); + if (rc) + goto out; + + sg_init_one(&sg, buf, len); + ahash_request_set_crypt(req, &sg, NULL, len); + + ahash_rc = crypto_ahash_update(req); + + /* wait for the update request to complete */ + rc = ahash_wait(ahash_rc, &res); + if (!rc) { + ahash_request_set_crypt(req, NULL, hash->digest, 0); + rc = ahash_wait(crypto_ahash_final(req), &res); + } +out: + ahash_request_free(req); + return rc; +} + +static int calc_buffer_ahash(const void *buf, loff_t len, + struct ima_digest_data *hash) +{ + struct crypto_ahash *tfm; + int rc; + + tfm = ima_alloc_atfm(hash->algo); + if (IS_ERR(tfm)) + return PTR_ERR(tfm); + + rc = calc_buffer_ahash_atfm(buf, len, hash, tfm); + + ima_free_atfm(tfm); + + return rc; +} + static int calc_buffer_shash_tfm(const void *buf, loff_t size, struct ima_digest_data *hash, struct crypto_shash *tfm) @@ -550,8 +607,8 @@ static int calc_buffer_shash_tfm(const void *buf, loff_t size, return rc; } -int ima_calc_buffer_hash(const void *buf, loff_t len, - struct ima_digest_data *hash) +static int calc_buffer_shash(const void *buf, loff_t len, + struct ima_digest_data *hash) { struct crypto_shash *tfm; int rc; @@ -566,6 +623,20 @@ int ima_calc_buffer_hash(const void *buf, loff_t len, return rc; } +int ima_calc_buffer_hash(const void *buf, loff_t len, + struct ima_digest_data *hash) +{ + int rc; + + if (ima_ahash_minsize && len >= ima_ahash_minsize) { + rc = calc_buffer_ahash(buf, len, hash); + if (!rc) + return 0; + } + + return calc_buffer_shash(buf, len, hash); +} + static void __init ima_pcrread(int idx, u8 *pcr) { if (!ima_used_chip) -- cgit v1.2.3 From cf2222178645e545e96717b2825601321ce4745c Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Thu, 14 Jan 2016 17:57:47 -0500 Subject: ima: define a new hook to measure and appraise a file already in memory This patch defines a new IMA hook ima_post_read_file() for measuring and appraising files read by the kernel. The caller loads the file into memory before calling this function, which calculates the hash followed by the normal IMA policy based processing. Changelog v5: - fail ima_post_read_file() if either file or buf is NULL v3: - rename ima_hash_and_process_file() to ima_post_read_file() v1: - split patch Signed-off-by: Mimi Zohar Acked-by: Dmitry Kasatkin --- include/linux/ima.h | 8 +++++++ include/linux/security.h | 1 + security/integrity/ima/ima.h | 4 +++- security/integrity/ima/ima_api.c | 6 +++-- security/integrity/ima/ima_appraise.c | 2 +- security/integrity/ima/ima_main.c | 45 ++++++++++++++++++++++++++++------- security/integrity/ima/ima_policy.c | 1 + security/integrity/integrity.h | 7 ++++-- security/security.c | 7 +++++- 9 files changed, 66 insertions(+), 15 deletions(-) (limited to 'security') diff --git a/include/linux/ima.h b/include/linux/ima.h index 120ccc53fcb7..d29a6a23fc19 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -20,6 +20,8 @@ extern void ima_file_free(struct file *file); extern int ima_file_mmap(struct file *file, unsigned long prot); extern int ima_module_check(struct file *file); extern int ima_fw_from_file(struct file *file, char *buf, size_t size); +extern int ima_post_read_file(struct file *file, void *buf, loff_t size, + enum kernel_read_file_id id); #else static inline int ima_bprm_check(struct linux_binprm *bprm) @@ -52,6 +54,12 @@ static inline int ima_fw_from_file(struct file *file, char *buf, size_t size) return 0; } +static inline int ima_post_read_file(struct file *file, void *buf, loff_t size, + enum kernel_read_file_id id) +{ + return 0; +} + #endif /* CONFIG_IMA */ #ifdef CONFIG_IMA_APPRAISE diff --git a/include/linux/security.h b/include/linux/security.h index b68ce94e4e00..d920718dc845 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -24,6 +24,7 @@ #include #include +#include #include #include #include diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index 2c5262f2823f..0b7134c04165 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -19,6 +19,7 @@ #include #include +#include #include #include #include @@ -152,7 +153,8 @@ enum ima_hooks { int ima_get_action(struct inode *inode, int mask, enum ima_hooks func); int ima_must_measure(struct inode *inode, int mask, enum ima_hooks func); int ima_collect_measurement(struct integrity_iint_cache *iint, - struct file *file, enum hash_algo algo); + struct file *file, void *buf, loff_t size, + enum hash_algo algo); void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file, const unsigned char *filename, struct evm_ima_xattr_data *xattr_value, diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c index 8750254506a9..370e42dfc5c5 100644 --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -188,7 +188,8 @@ int ima_get_action(struct inode *inode, int mask, enum ima_hooks func) * Return 0 on success, error code otherwise */ int ima_collect_measurement(struct integrity_iint_cache *iint, - struct file *file, enum hash_algo algo) + struct file *file, void *buf, loff_t size, + enum hash_algo algo) { const char *audit_cause = "failed"; struct inode *inode = file_inode(file); @@ -210,7 +211,8 @@ int ima_collect_measurement(struct integrity_iint_cache *iint, hash.hdr.algo = algo; - result = ima_calc_file_hash(file, &hash.hdr); + result = (!buf) ? ima_calc_file_hash(file, &hash.hdr) : + ima_calc_buffer_hash(buf, size, &hash.hdr); if (!result) { int length = sizeof(hash.hdr) + hash.hdr.length; void *tmpbuf = krealloc(iint->ima_hash, length, diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index 288844908788..cb0d0ff1137b 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -300,7 +300,7 @@ void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file) if (iint->flags & IMA_DIGSIG) return; - rc = ima_collect_measurement(iint, file, ima_hash_algo); + rc = ima_collect_measurement(iint, file, NULL, 0, ima_hash_algo); if (rc < 0) return; diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 1be99a27a7f3..757765354158 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -153,8 +153,8 @@ void ima_file_free(struct file *file) ima_check_last_writer(iint, inode, file); } -static int process_measurement(struct file *file, int mask, - enum ima_hooks func, int opened) +static int process_measurement(struct file *file, char *buf, loff_t size, + int mask, enum ima_hooks func, int opened) { struct inode *inode = file_inode(file); struct integrity_iint_cache *iint = NULL; @@ -226,7 +226,7 @@ static int process_measurement(struct file *file, int mask, hash_algo = ima_get_hash_algo(xattr_value, xattr_len); - rc = ima_collect_measurement(iint, file, hash_algo); + rc = ima_collect_measurement(iint, file, buf, size, hash_algo); if (rc != 0) { if (file->f_flags & O_DIRECT) rc = (iint->flags & IMA_PERMIT_DIRECTIO) ? 0 : -EACCES; @@ -273,7 +273,8 @@ out: int ima_file_mmap(struct file *file, unsigned long prot) { if (file && (prot & PROT_EXEC)) - return process_measurement(file, MAY_EXEC, MMAP_CHECK, 0); + return process_measurement(file, NULL, 0, MAY_EXEC, + MMAP_CHECK, 0); return 0; } @@ -292,7 +293,8 @@ int ima_file_mmap(struct file *file, unsigned long prot) */ int ima_bprm_check(struct linux_binprm *bprm) { - return process_measurement(bprm->file, MAY_EXEC, BPRM_CHECK, 0); + return process_measurement(bprm->file, NULL, 0, MAY_EXEC, + BPRM_CHECK, 0); } /** @@ -307,7 +309,7 @@ int ima_bprm_check(struct linux_binprm *bprm) */ int ima_file_check(struct file *file, int mask, int opened) { - return process_measurement(file, + return process_measurement(file, NULL, 0, mask & (MAY_READ | MAY_WRITE | MAY_EXEC), FILE_CHECK, opened); } @@ -332,7 +334,7 @@ int ima_module_check(struct file *file) #endif return 0; /* We rely on module signature checking */ } - return process_measurement(file, MAY_EXEC, MODULE_CHECK, 0); + return process_measurement(file, NULL, 0, MAY_EXEC, MODULE_CHECK, 0); } int ima_fw_from_file(struct file *file, char *buf, size_t size) @@ -343,7 +345,34 @@ int ima_fw_from_file(struct file *file, char *buf, size_t size) return -EACCES; /* INTEGRITY_UNKNOWN */ return 0; } - return process_measurement(file, MAY_EXEC, FIRMWARE_CHECK, 0); + return process_measurement(file, NULL, 0, MAY_EXEC, FIRMWARE_CHECK, 0); +} + +/** + * ima_post_read_file - in memory collect/appraise/audit measurement + * @file: pointer to the file to be measured/appraised/audit + * @buf: pointer to in memory file contents + * @size: size of in memory file contents + * @read_id: caller identifier + * + * Measure/appraise/audit in memory file based on policy. Policy rules + * are written in terms of a policy identifier. + * + * On success return 0. On integrity appraisal error, assuming the file + * is in policy and IMA-appraisal is in enforcing mode, return -EACCES. + */ +int ima_post_read_file(struct file *file, void *buf, loff_t size, + enum kernel_read_file_id read_id) +{ + enum ima_hooks func = FILE_CHECK; + + if (!file || !buf || size == 0) { /* should never happen */ + if (ima_appraise & IMA_APPRAISE_ENFORCE) + return -EACCES; + return 0; + } + + return process_measurement(file, buf, size, MAY_READ, func, 0); } static int __init init_ima(void) diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index b089ebef6648..cfbe86f476d0 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -12,6 +12,7 @@ */ #include #include +#include #include #include #include diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h index 5efe2ecc538d..9a0ea4c4e3dd 100644 --- a/security/integrity/integrity.h +++ b/security/integrity/integrity.h @@ -49,12 +49,14 @@ #define IMA_MODULE_APPRAISED 0x00008000 #define IMA_FIRMWARE_APPRAISE 0x00010000 #define IMA_FIRMWARE_APPRAISED 0x00020000 +#define IMA_READ_APPRAISE 0x00040000 +#define IMA_READ_APPRAISED 0x00080000 #define IMA_APPRAISE_SUBMASK (IMA_FILE_APPRAISE | IMA_MMAP_APPRAISE | \ IMA_BPRM_APPRAISE | IMA_MODULE_APPRAISE | \ - IMA_FIRMWARE_APPRAISE) + IMA_FIRMWARE_APPRAISE | IMA_READ_APPRAISE) #define IMA_APPRAISED_SUBMASK (IMA_FILE_APPRAISED | IMA_MMAP_APPRAISED | \ IMA_BPRM_APPRAISED | IMA_MODULE_APPRAISED | \ - IMA_FIRMWARE_APPRAISED) + IMA_FIRMWARE_APPRAISED | IMA_READ_APPRAISED) enum evm_ima_xattr_type { IMA_XATTR_DIGEST = 0x01, @@ -111,6 +113,7 @@ struct integrity_iint_cache { enum integrity_status ima_bprm_status:4; enum integrity_status ima_module_status:4; enum integrity_status ima_firmware_status:4; + enum integrity_status ima_read_status:4; enum integrity_status evm_status:4; struct ima_digest_data *ima_hash; }; diff --git a/security/security.c b/security/security.c index 5b96eabaafd4..ef4c65a9fd17 100644 --- a/security/security.c +++ b/security/security.c @@ -913,7 +913,12 @@ int security_kernel_module_from_file(struct file *file) int security_kernel_post_read_file(struct file *file, char *buf, loff_t size, enum kernel_read_file_id id) { - return call_int_hook(kernel_post_read_file, 0, file, buf, size, id); + int ret; + + ret = call_int_hook(kernel_post_read_file, 0, file, buf, size, id); + if (ret) + return ret; + return ima_post_read_file(file, buf, size, id); } EXPORT_SYMBOL_GPL(security_kernel_post_read_file); -- cgit v1.2.3 From e40ba6d56b41754b37b995dbc8035b2b3a6afd8a Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Thu, 19 Nov 2015 12:39:22 -0500 Subject: firmware: replace call to fw_read_file_contents() with kernel version Replace the fw_read_file_contents with kernel_file_read_from_path(). Although none of the upstreamed LSMs define a kernel_fw_from_file hook, IMA is called by the security function to prevent unsigned firmware from being loaded and to measure/appraise signed firmware, based on policy. Instead of reading the firmware twice, once for measuring/appraising the firmware and again for reading the firmware contents into memory, the kernel_post_read_file() security hook calculates the file hash based on the in memory file buffer. The firmware is read once. This patch removes the LSM kernel_fw_from_file() hook and security call. Changelog v4+: - revert dropped buf->size assignment - reported by Sergey Senozhatsky v3: - remove kernel_fw_from_file hook - use kernel_file_read_from_path() - requested by Luis v2: - reordered and squashed firmware patches - fix MAX firmware size (Kees Cook) Signed-off-by: Mimi Zohar Acked-by: Kees Cook Acked-by: Luis R. Rodriguez --- drivers/base/firmware_class.c | 52 ++++++++------------------------------- include/linux/fs.h | 1 + include/linux/ima.h | 6 ----- include/linux/lsm_hooks.h | 11 --------- include/linux/security.h | 7 ------ security/integrity/ima/ima_main.c | 21 ++++++++-------- security/security.c | 13 ---------- 7 files changed, 21 insertions(+), 90 deletions(-) (limited to 'security') diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c index c743a2f18c33..a414008ea64c 100644 --- a/drivers/base/firmware_class.c +++ b/drivers/base/firmware_class.c @@ -23,6 +23,7 @@ #include #include #include +#include #include #include #include @@ -291,37 +292,6 @@ static const char * const fw_path[] = { module_param_string(path, fw_path_para, sizeof(fw_path_para), 0644); MODULE_PARM_DESC(path, "customized firmware image search path with a higher priority than default path"); -static int fw_read_file_contents(struct file *file, struct firmware_buf *fw_buf) -{ - int size; - char *buf; - int rc; - - if (!S_ISREG(file_inode(file)->i_mode)) - return -EINVAL; - size = i_size_read(file_inode(file)); - if (size <= 0) - return -EINVAL; - buf = vmalloc(size); - if (!buf) - return -ENOMEM; - rc = kernel_read(file, 0, buf, size); - if (rc != size) { - if (rc > 0) - rc = -EIO; - goto fail; - } - rc = security_kernel_fw_from_file(file, buf, size); - if (rc) - goto fail; - fw_buf->data = buf; - fw_buf->size = size; - return 0; -fail: - vfree(buf); - return rc; -} - static void fw_finish_direct_load(struct device *device, struct firmware_buf *buf) { @@ -334,6 +304,7 @@ static void fw_finish_direct_load(struct device *device, static int fw_get_filesystem_firmware(struct device *device, struct firmware_buf *buf) { + loff_t size; int i, len; int rc = -ENOENT; char *path; @@ -343,8 +314,6 @@ static int fw_get_filesystem_firmware(struct device *device, return -ENOMEM; for (i = 0; i < ARRAY_SIZE(fw_path); i++) { - struct file *file; - /* skip the unset customized path */ if (!fw_path[i][0]) continue; @@ -356,18 +325,16 @@ static int fw_get_filesystem_firmware(struct device *device, break; } - file = filp_open(path, O_RDONLY, 0); - if (IS_ERR(file)) - continue; - rc = fw_read_file_contents(file, buf); - fput(file); + buf->size = 0; + rc = kernel_read_file_from_path(path, &buf->data, &size, + INT_MAX, READING_FIRMWARE); if (rc) { dev_warn(device, "loading %s failed with error %d\n", path, rc); continue; } - dev_dbg(device, "direct-loading %s\n", - buf->fw_id); + dev_dbg(device, "direct-loading %s\n", buf->fw_id); + buf->size = size; fw_finish_direct_load(device, buf); break; } @@ -689,8 +656,9 @@ static ssize_t firmware_loading_store(struct device *dev, dev_err(dev, "%s: map pages failed\n", __func__); else - rc = security_kernel_fw_from_file(NULL, - fw_buf->data, fw_buf->size); + rc = security_kernel_post_read_file(NULL, + fw_buf->data, fw_buf->size, + READING_FIRMWARE); /* * Same logic as fw_load_abort, only the DONE bit diff --git a/include/linux/fs.h b/include/linux/fs.h index 00fa5c45fd63..c8bc4d8c843f 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2577,6 +2577,7 @@ static inline void i_readcount_inc(struct inode *inode) extern int do_pipe_flags(int *, int); enum kernel_read_file_id { + READING_FIRMWARE = 1, READING_MAX_ID }; diff --git a/include/linux/ima.h b/include/linux/ima.h index d29a6a23fc19..7aea4863c244 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -19,7 +19,6 @@ extern int ima_file_check(struct file *file, int mask, int opened); extern void ima_file_free(struct file *file); extern int ima_file_mmap(struct file *file, unsigned long prot); extern int ima_module_check(struct file *file); -extern int ima_fw_from_file(struct file *file, char *buf, size_t size); extern int ima_post_read_file(struct file *file, void *buf, loff_t size, enum kernel_read_file_id id); @@ -49,11 +48,6 @@ static inline int ima_module_check(struct file *file) return 0; } -static inline int ima_fw_from_file(struct file *file, char *buf, size_t size) -{ - return 0; -} - static inline int ima_post_read_file(struct file *file, void *buf, loff_t size, enum kernel_read_file_id id) { diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 2337f33913c1..7d04a1220223 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -541,15 +541,6 @@ * @inode points to the inode to use as a reference. * The current task must be the one that nominated @inode. * Return 0 if successful. - * @kernel_fw_from_file: - * Load firmware from userspace (not called for built-in firmware). - * @file contains the file structure pointing to the file containing - * the firmware to load. This argument will be NULL if the firmware - * was loaded via the uevent-triggered blob-based interface exposed - * by CONFIG_FW_LOADER_USER_HELPER. - * @buf pointer to buffer containing firmware contents. - * @size length of the firmware contents. - * Return 0 if permission is granted. * @kernel_module_request: * Ability to trigger the kernel to automatically upcall to userspace for * userspace to load a kernel module with the given name. @@ -1462,7 +1453,6 @@ union security_list_options { void (*cred_transfer)(struct cred *new, const struct cred *old); int (*kernel_act_as)(struct cred *new, u32 secid); int (*kernel_create_files_as)(struct cred *new, struct inode *inode); - int (*kernel_fw_from_file)(struct file *file, char *buf, size_t size); int (*kernel_module_request)(char *kmod_name); int (*kernel_module_from_file)(struct file *file); int (*kernel_post_read_file)(struct file *file, char *buf, loff_t size, @@ -1725,7 +1715,6 @@ struct security_hook_heads { struct list_head cred_transfer; struct list_head kernel_act_as; struct list_head kernel_create_files_as; - struct list_head kernel_fw_from_file; struct list_head kernel_post_read_file; struct list_head kernel_module_request; struct list_head kernel_module_from_file; diff --git a/include/linux/security.h b/include/linux/security.h index d920718dc845..cee1349e1155 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -300,7 +300,6 @@ int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp); void security_transfer_creds(struct cred *new, const struct cred *old); int security_kernel_act_as(struct cred *new, u32 secid); int security_kernel_create_files_as(struct cred *new, struct inode *inode); -int security_kernel_fw_from_file(struct file *file, char *buf, size_t size); int security_kernel_module_request(char *kmod_name); int security_kernel_module_from_file(struct file *file); int security_kernel_post_read_file(struct file *file, char *buf, loff_t size, @@ -854,12 +853,6 @@ static inline int security_kernel_create_files_as(struct cred *cred, return 0; } -static inline int security_kernel_fw_from_file(struct file *file, - char *buf, size_t size) -{ - return 0; -} - static inline int security_kernel_module_request(char *kmod_name) { return 0; diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 757765354158..e9651be17b72 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -337,17 +337,6 @@ int ima_module_check(struct file *file) return process_measurement(file, NULL, 0, MAY_EXEC, MODULE_CHECK, 0); } -int ima_fw_from_file(struct file *file, char *buf, size_t size) -{ - if (!file) { - if ((ima_appraise & IMA_APPRAISE_FIRMWARE) && - (ima_appraise & IMA_APPRAISE_ENFORCE)) - return -EACCES; /* INTEGRITY_UNKNOWN */ - return 0; - } - return process_measurement(file, NULL, 0, MAY_EXEC, FIRMWARE_CHECK, 0); -} - /** * ima_post_read_file - in memory collect/appraise/audit measurement * @file: pointer to the file to be measured/appraised/audit @@ -366,12 +355,22 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size, { enum ima_hooks func = FILE_CHECK; + if (!file && read_id == READING_FIRMWARE) { + if ((ima_appraise & IMA_APPRAISE_FIRMWARE) && + (ima_appraise & IMA_APPRAISE_ENFORCE)) + return -EACCES; /* INTEGRITY_UNKNOWN */ + return 0; + } + if (!file || !buf || size == 0) { /* should never happen */ if (ima_appraise & IMA_APPRAISE_ENFORCE) return -EACCES; return 0; } + if (read_id == READING_FIRMWARE) + func = FIRMWARE_CHECK; + return process_measurement(file, buf, size, MAY_READ, func, 0); } diff --git a/security/security.c b/security/security.c index ef4c65a9fd17..cd85be61c416 100644 --- a/security/security.c +++ b/security/security.c @@ -884,17 +884,6 @@ int security_kernel_create_files_as(struct cred *new, struct inode *inode) return call_int_hook(kernel_create_files_as, 0, new, inode); } -int security_kernel_fw_from_file(struct file *file, char *buf, size_t size) -{ - int ret; - - ret = call_int_hook(kernel_fw_from_file, 0, file, buf, size); - if (ret) - return ret; - return ima_fw_from_file(file, buf, size); -} -EXPORT_SYMBOL_GPL(security_kernel_fw_from_file); - int security_kernel_module_request(char *kmod_name) { return call_int_hook(kernel_module_request, 0, kmod_name); @@ -1703,8 +1692,6 @@ struct security_hook_heads security_hook_heads = { LIST_HEAD_INIT(security_hook_heads.kernel_act_as), .kernel_create_files_as = LIST_HEAD_INIT(security_hook_heads.kernel_create_files_as), - .kernel_fw_from_file = - LIST_HEAD_INIT(security_hook_heads.kernel_fw_from_file), .kernel_module_request = LIST_HEAD_INIT(security_hook_heads.kernel_module_request), .kernel_module_from_file = -- cgit v1.2.3 From 39eeb4fb97f60dbdfc823c1a673a8844b9226b60 Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Sat, 30 Jan 2016 22:23:26 -0500 Subject: security: define kernel_read_file hook The kernel_read_file security hook is called prior to reading the file into memory. Changelog v4+: - export security_kernel_read_file() Signed-off-by: Mimi Zohar Acked-by: Kees Cook Acked-by: Luis R. Rodriguez Acked-by: Casey Schaufler --- fs/exec.c | 4 ++++ include/linux/ima.h | 6 ++++++ include/linux/lsm_hooks.h | 8 ++++++++ include/linux/security.h | 7 +++++++ security/integrity/ima/ima_main.c | 16 ++++++++++++++++ security/security.c | 13 +++++++++++++ 6 files changed, 54 insertions(+) (limited to 'security') diff --git a/fs/exec.c b/fs/exec.c index 64cb3bc788c1..8aaa38666119 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -842,6 +842,10 @@ int kernel_read_file(struct file *file, void **buf, loff_t *size, if (!S_ISREG(file_inode(file)->i_mode) || max_size < 0) return -EINVAL; + ret = security_kernel_read_file(file, id); + if (ret) + return ret; + i_size = i_size_read(file_inode(file)); if (max_size > 0 && i_size > max_size) return -EFBIG; diff --git a/include/linux/ima.h b/include/linux/ima.h index 7aea4863c244..6adcaea8101c 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -19,6 +19,7 @@ extern int ima_file_check(struct file *file, int mask, int opened); extern void ima_file_free(struct file *file); extern int ima_file_mmap(struct file *file, unsigned long prot); extern int ima_module_check(struct file *file); +extern int ima_read_file(struct file *file, enum kernel_read_file_id id); extern int ima_post_read_file(struct file *file, void *buf, loff_t size, enum kernel_read_file_id id); @@ -48,6 +49,11 @@ static inline int ima_module_check(struct file *file) return 0; } +static inline int ima_read_file(struct file *file, enum kernel_read_file_id id) +{ + return 0; +} + static inline int ima_post_read_file(struct file *file, void *buf, loff_t size, enum kernel_read_file_id id) { diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 7d04a1220223..d32b7bd13635 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -552,6 +552,12 @@ * the kernel module to load. If the module is being loaded from a blob, * this argument will be NULL. * Return 0 if permission is granted. + * @kernel_read_file: + * Read a file specified by userspace. + * @file contains the file structure pointing to the file being read + * by the kernel. + * @id kernel read file identifier + * Return 0 if permission is granted. * @kernel_post_read_file: * Read a file specified by userspace. * @file contains the file structure pointing to the file being read @@ -1455,6 +1461,7 @@ union security_list_options { int (*kernel_create_files_as)(struct cred *new, struct inode *inode); int (*kernel_module_request)(char *kmod_name); int (*kernel_module_from_file)(struct file *file); + int (*kernel_read_file)(struct file *file, enum kernel_read_file_id id); int (*kernel_post_read_file)(struct file *file, char *buf, loff_t size, enum kernel_read_file_id id); int (*task_fix_setuid)(struct cred *new, const struct cred *old, @@ -1715,6 +1722,7 @@ struct security_hook_heads { struct list_head cred_transfer; struct list_head kernel_act_as; struct list_head kernel_create_files_as; + struct list_head kernel_read_file; struct list_head kernel_post_read_file; struct list_head kernel_module_request; struct list_head kernel_module_from_file; diff --git a/include/linux/security.h b/include/linux/security.h index cee1349e1155..071fb747fdbb 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -302,6 +302,7 @@ int security_kernel_act_as(struct cred *new, u32 secid); int security_kernel_create_files_as(struct cred *new, struct inode *inode); int security_kernel_module_request(char *kmod_name); int security_kernel_module_from_file(struct file *file); +int security_kernel_read_file(struct file *file, enum kernel_read_file_id id); int security_kernel_post_read_file(struct file *file, char *buf, loff_t size, enum kernel_read_file_id id); int security_task_fix_setuid(struct cred *new, const struct cred *old, @@ -863,6 +864,12 @@ static inline int security_kernel_module_from_file(struct file *file) return 0; } +static inline int security_kernel_read_file(struct file *file, + enum kernel_read_file_id id) +{ + return 0; +} + static inline int security_kernel_post_read_file(struct file *file, char *buf, loff_t size, enum kernel_read_file_id id) diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index e9651be17b72..bbb80df28fb1 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -337,6 +337,22 @@ int ima_module_check(struct file *file) return process_measurement(file, NULL, 0, MAY_EXEC, MODULE_CHECK, 0); } +/** + * ima_read_file - pre-measure/appraise hook decision based on policy + * @file: pointer to the file to be measured/appraised/audit + * @read_id: caller identifier + * + * Permit reading a file based on policy. The policy rules are written + * in terms of the policy identifier. Appraising the integrity of + * a file requires a file descriptor. + * + * For permission return 0, otherwise return -EACCES. + */ +int ima_read_file(struct file *file, enum kernel_read_file_id read_id) +{ + return 0; +} + /** * ima_post_read_file - in memory collect/appraise/audit measurement * @file: pointer to the file to be measured/appraised/audit diff --git a/security/security.c b/security/security.c index cd85be61c416..8e699f98a600 100644 --- a/security/security.c +++ b/security/security.c @@ -899,6 +899,17 @@ int security_kernel_module_from_file(struct file *file) return ima_module_check(file); } +int security_kernel_read_file(struct file *file, enum kernel_read_file_id id) +{ + int ret; + + ret = call_int_hook(kernel_read_file, 0, file, id); + if (ret) + return ret; + return ima_read_file(file, id); +} +EXPORT_SYMBOL_GPL(security_kernel_read_file); + int security_kernel_post_read_file(struct file *file, char *buf, loff_t size, enum kernel_read_file_id id) { @@ -1696,6 +1707,8 @@ struct security_hook_heads security_hook_heads = { LIST_HEAD_INIT(security_hook_heads.kernel_module_request), .kernel_module_from_file = LIST_HEAD_INIT(security_hook_heads.kernel_module_from_file), + .kernel_read_file = + LIST_HEAD_INIT(security_hook_heads.kernel_read_file), .kernel_post_read_file = LIST_HEAD_INIT(security_hook_heads.kernel_post_read_file), .task_fix_setuid = -- cgit v1.2.3 From a1db74209483a24c861c848b4bb79a4d945ef6fa Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Wed, 30 Dec 2015 07:35:30 -0500 Subject: module: replace copy_module_from_fd with kernel version Replace copy_module_from_fd() with kernel_read_file_from_fd(). Although none of the upstreamed LSMs define a kernel_module_from_file hook, IMA is called, based on policy, to prevent unsigned kernel modules from being loaded by the original kernel module syscall and to measure/appraise signed kernel modules. The security function security_kernel_module_from_file() was called prior to reading a kernel module. Preventing unsigned kernel modules from being loaded by the original kernel module syscall remains on the pre-read kernel_read_file() security hook. Instead of reading the kernel module twice, once for measuring/appraising and again for loading the kernel module, the signature validation is moved to the kernel_post_read_file() security hook. This patch removes the security_kernel_module_from_file() hook and security call. Signed-off-by: Mimi Zohar Acked-by: Kees Cook Acked-by: Luis R. Rodriguez Cc: Rusty Russell --- include/linux/fs.h | 1 + include/linux/ima.h | 6 ---- include/linux/lsm_hooks.h | 7 ---- include/linux/security.h | 5 --- kernel/module.c | 68 +++++---------------------------------- security/integrity/ima/ima_main.c | 35 ++++++++------------ security/security.c | 12 ------- 7 files changed, 22 insertions(+), 112 deletions(-) (limited to 'security') diff --git a/include/linux/fs.h b/include/linux/fs.h index 9c85deae1bf2..fb08b668c37a 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2578,6 +2578,7 @@ extern int do_pipe_flags(int *, int); enum kernel_read_file_id { READING_FIRMWARE = 1, + READING_MODULE, READING_MAX_ID }; diff --git a/include/linux/ima.h b/include/linux/ima.h index 6adcaea8101c..e6516cbbe9bf 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -18,7 +18,6 @@ extern int ima_bprm_check(struct linux_binprm *bprm); extern int ima_file_check(struct file *file, int mask, int opened); extern void ima_file_free(struct file *file); extern int ima_file_mmap(struct file *file, unsigned long prot); -extern int ima_module_check(struct file *file); extern int ima_read_file(struct file *file, enum kernel_read_file_id id); extern int ima_post_read_file(struct file *file, void *buf, loff_t size, enum kernel_read_file_id id); @@ -44,11 +43,6 @@ static inline int ima_file_mmap(struct file *file, unsigned long prot) return 0; } -static inline int ima_module_check(struct file *file) -{ - return 0; -} - static inline int ima_read_file(struct file *file, enum kernel_read_file_id id) { return 0; diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index d32b7bd13635..cdee11cbcdf1 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -546,12 +546,6 @@ * userspace to load a kernel module with the given name. * @kmod_name name of the module requested by the kernel * Return 0 if successful. - * @kernel_module_from_file: - * Load a kernel module from userspace. - * @file contains the file structure pointing to the file containing - * the kernel module to load. If the module is being loaded from a blob, - * this argument will be NULL. - * Return 0 if permission is granted. * @kernel_read_file: * Read a file specified by userspace. * @file contains the file structure pointing to the file being read @@ -1725,7 +1719,6 @@ struct security_hook_heads { struct list_head kernel_read_file; struct list_head kernel_post_read_file; struct list_head kernel_module_request; - struct list_head kernel_module_from_file; struct list_head task_fix_setuid; struct list_head task_setpgid; struct list_head task_getpgid; diff --git a/include/linux/security.h b/include/linux/security.h index 071fb747fdbb..157f0cb1e4d2 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -859,11 +859,6 @@ static inline int security_kernel_module_request(char *kmod_name) return 0; } -static inline int security_kernel_module_from_file(struct file *file) -{ - return 0; -} - static inline int security_kernel_read_file(struct file *file, enum kernel_read_file_id id) { diff --git a/kernel/module.c b/kernel/module.c index 8358f4697c0c..955410928696 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2654,7 +2654,7 @@ static int copy_module_from_user(const void __user *umod, unsigned long len, if (info->len < sizeof(*(info->hdr))) return -ENOEXEC; - err = security_kernel_module_from_file(NULL); + err = security_kernel_read_file(NULL, READING_MODULE); if (err) return err; @@ -2672,63 +2672,6 @@ static int copy_module_from_user(const void __user *umod, unsigned long len, return 0; } -/* Sets info->hdr and info->len. */ -static int copy_module_from_fd(int fd, struct load_info *info) -{ - struct fd f = fdget(fd); - int err; - struct kstat stat; - loff_t pos; - ssize_t bytes = 0; - - if (!f.file) - return -ENOEXEC; - - err = security_kernel_module_from_file(f.file); - if (err) - goto out; - - err = vfs_getattr(&f.file->f_path, &stat); - if (err) - goto out; - - if (stat.size > INT_MAX) { - err = -EFBIG; - goto out; - } - - /* Don't hand 0 to vmalloc, it whines. */ - if (stat.size == 0) { - err = -EINVAL; - goto out; - } - - info->hdr = vmalloc(stat.size); - if (!info->hdr) { - err = -ENOMEM; - goto out; - } - - pos = 0; - while (pos < stat.size) { - bytes = kernel_read(f.file, pos, (char *)(info->hdr) + pos, - stat.size - pos); - if (bytes < 0) { - vfree(info->hdr); - err = bytes; - goto out; - } - if (bytes == 0) - break; - pos += bytes; - } - info->len = pos; - -out: - fdput(f); - return err; -} - static void free_copy(struct load_info *info) { vfree(info->hdr); @@ -3589,8 +3532,10 @@ SYSCALL_DEFINE3(init_module, void __user *, umod, SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags) { - int err; struct load_info info = { }; + loff_t size; + void *hdr; + int err; err = may_init_module(); if (err) @@ -3602,9 +3547,12 @@ SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags) |MODULE_INIT_IGNORE_VERMAGIC)) return -EINVAL; - err = copy_module_from_fd(fd, &info); + err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX, + READING_MODULE); if (err) return err; + info.hdr = hdr; + info.len = size; return load_module(&info, uargs, flags); } diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index bbb80df28fb1..5da0b9c00072 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -315,28 +315,6 @@ int ima_file_check(struct file *file, int mask, int opened) } EXPORT_SYMBOL_GPL(ima_file_check); -/** - * ima_module_check - based on policy, collect/store/appraise measurement. - * @file: pointer to the file to be measured/appraised - * - * Measure/appraise kernel modules based on policy. - * - * On success return 0. On integrity appraisal error, assuming the file - * is in policy and IMA-appraisal is in enforcing mode, return -EACCES. - */ -int ima_module_check(struct file *file) -{ - if (!file) { -#ifndef CONFIG_MODULE_SIG_FORCE - if ((ima_appraise & IMA_APPRAISE_MODULES) && - (ima_appraise & IMA_APPRAISE_ENFORCE)) - return -EACCES; /* INTEGRITY_UNKNOWN */ -#endif - return 0; /* We rely on module signature checking */ - } - return process_measurement(file, NULL, 0, MAY_EXEC, MODULE_CHECK, 0); -} - /** * ima_read_file - pre-measure/appraise hook decision based on policy * @file: pointer to the file to be measured/appraised/audit @@ -350,6 +328,14 @@ int ima_module_check(struct file *file) */ int ima_read_file(struct file *file, enum kernel_read_file_id read_id) { + if (!file && read_id == READING_MODULE) { +#ifndef CONFIG_MODULE_SIG_FORCE + if ((ima_appraise & IMA_APPRAISE_MODULES) && + (ima_appraise & IMA_APPRAISE_ENFORCE)) + return -EACCES; /* INTEGRITY_UNKNOWN */ +#endif + return 0; /* We rely on module signature checking */ + } return 0; } @@ -378,6 +364,9 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size, return 0; } + if (!file && read_id == READING_MODULE) /* MODULE_SIG_FORCE enabled */ + return 0; + if (!file || !buf || size == 0) { /* should never happen */ if (ima_appraise & IMA_APPRAISE_ENFORCE) return -EACCES; @@ -386,6 +375,8 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size, if (read_id == READING_FIRMWARE) func = FIRMWARE_CHECK; + else if (read_id == READING_MODULE) + func = MODULE_CHECK; return process_measurement(file, buf, size, MAY_READ, func, 0); } diff --git a/security/security.c b/security/security.c index 8e699f98a600..3644b0344d29 100644 --- a/security/security.c +++ b/security/security.c @@ -889,16 +889,6 @@ int security_kernel_module_request(char *kmod_name) return call_int_hook(kernel_module_request, 0, kmod_name); } -int security_kernel_module_from_file(struct file *file) -{ - int ret; - - ret = call_int_hook(kernel_module_from_file, 0, file); - if (ret) - return ret; - return ima_module_check(file); -} - int security_kernel_read_file(struct file *file, enum kernel_read_file_id id) { int ret; @@ -1705,8 +1695,6 @@ struct security_hook_heads security_hook_heads = { LIST_HEAD_INIT(security_hook_heads.kernel_create_files_as), .kernel_module_request = LIST_HEAD_INIT(security_hook_heads.kernel_module_request), - .kernel_module_from_file = - LIST_HEAD_INIT(security_hook_heads.kernel_module_from_file), .kernel_read_file = LIST_HEAD_INIT(security_hook_heads.kernel_read_file), .kernel_post_read_file = -- cgit v1.2.3 From c6af8efe97d87fa308eb1bbd0cf4feb820a4d622 Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Thu, 19 Nov 2015 12:39:22 -0500 Subject: ima: remove firmware and module specific cached status info Each time a file is read by the kernel, the file should be re-measured and the file signature re-appraised, based on policy. As there is no need to preserve the status information, this patch replaces the firmware and module specific cache status with a generic one named read_file. This change simplifies adding support for other files read by the kernel. Signed-off-by: Mimi Zohar Acked-by: Petko Manolov Acked-by: Dmitry Kasatkin --- security/integrity/iint.c | 4 ++-- security/integrity/ima/ima.h | 3 ++- security/integrity/ima/ima_appraise.c | 35 ++++++++++++++++------------------- security/integrity/ima/ima_policy.c | 9 ++++----- security/integrity/integrity.h | 16 ++++------------ 5 files changed, 28 insertions(+), 39 deletions(-) (limited to 'security') diff --git a/security/integrity/iint.c b/security/integrity/iint.c index 8f1ab37f2897..345b75997e4c 100644 --- a/security/integrity/iint.c +++ b/security/integrity/iint.c @@ -77,7 +77,7 @@ static void iint_free(struct integrity_iint_cache *iint) iint->ima_file_status = INTEGRITY_UNKNOWN; iint->ima_mmap_status = INTEGRITY_UNKNOWN; iint->ima_bprm_status = INTEGRITY_UNKNOWN; - iint->ima_module_status = INTEGRITY_UNKNOWN; + iint->ima_read_status = INTEGRITY_UNKNOWN; iint->evm_status = INTEGRITY_UNKNOWN; kmem_cache_free(iint_cache, iint); } @@ -157,7 +157,7 @@ static void init_once(void *foo) iint->ima_file_status = INTEGRITY_UNKNOWN; iint->ima_mmap_status = INTEGRITY_UNKNOWN; iint->ima_bprm_status = INTEGRITY_UNKNOWN; - iint->ima_module_status = INTEGRITY_UNKNOWN; + iint->ima_read_status = INTEGRITY_UNKNOWN; iint->evm_status = INTEGRITY_UNKNOWN; } diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index 0b7134c04165..a5d25921ee3c 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -144,9 +144,10 @@ enum ima_hooks { FILE_CHECK = 1, MMAP_CHECK, BPRM_CHECK, + POST_SETATTR, MODULE_CHECK, FIRMWARE_CHECK, - POST_SETATTR + MAX_CHECK }; /* LIM API function definitions */ diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index cb0d0ff1137b..6b4694aedae8 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -74,13 +74,12 @@ enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint, return iint->ima_mmap_status; case BPRM_CHECK: return iint->ima_bprm_status; - case MODULE_CHECK: - return iint->ima_module_status; - case FIRMWARE_CHECK: - return iint->ima_firmware_status; case FILE_CHECK: - default: + case POST_SETATTR: return iint->ima_file_status; + case MODULE_CHECK ... MAX_CHECK - 1: + default: + return iint->ima_read_status; } } @@ -95,15 +94,14 @@ static void ima_set_cache_status(struct integrity_iint_cache *iint, case BPRM_CHECK: iint->ima_bprm_status = status; break; - case MODULE_CHECK: - iint->ima_module_status = status; - break; - case FIRMWARE_CHECK: - iint->ima_firmware_status = status; - break; case FILE_CHECK: - default: + case POST_SETATTR: iint->ima_file_status = status; + break; + case MODULE_CHECK ... MAX_CHECK - 1: + default: + iint->ima_read_status = status; + break; } } @@ -117,15 +115,14 @@ static void ima_cache_flags(struct integrity_iint_cache *iint, case BPRM_CHECK: iint->flags |= (IMA_BPRM_APPRAISED | IMA_APPRAISED); break; - case MODULE_CHECK: - iint->flags |= (IMA_MODULE_APPRAISED | IMA_APPRAISED); - break; - case FIRMWARE_CHECK: - iint->flags |= (IMA_FIRMWARE_APPRAISED | IMA_APPRAISED); - break; case FILE_CHECK: - default: + case POST_SETATTR: iint->flags |= (IMA_FILE_APPRAISED | IMA_APPRAISED); + break; + case MODULE_CHECK ... MAX_CHECK - 1: + default: + iint->flags |= (IMA_READ_APPRAISED | IMA_APPRAISED); + break; } } diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index cfbe86f476d0..7571ce8841ff 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -300,13 +300,12 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func) return IMA_MMAP_APPRAISE; case BPRM_CHECK: return IMA_BPRM_APPRAISE; - case MODULE_CHECK: - return IMA_MODULE_APPRAISE; - case FIRMWARE_CHECK: - return IMA_FIRMWARE_APPRAISE; case FILE_CHECK: - default: + case POST_SETATTR: return IMA_FILE_APPRAISE; + case MODULE_CHECK ... MAX_CHECK - 1: + default: + return IMA_READ_APPRAISE; } } diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h index 9a0ea4c4e3dd..c7a111cc7d89 100644 --- a/security/integrity/integrity.h +++ b/security/integrity/integrity.h @@ -45,18 +45,12 @@ #define IMA_MMAP_APPRAISED 0x00000800 #define IMA_BPRM_APPRAISE 0x00001000 #define IMA_BPRM_APPRAISED 0x00002000 -#define IMA_MODULE_APPRAISE 0x00004000 -#define IMA_MODULE_APPRAISED 0x00008000 -#define IMA_FIRMWARE_APPRAISE 0x00010000 -#define IMA_FIRMWARE_APPRAISED 0x00020000 -#define IMA_READ_APPRAISE 0x00040000 -#define IMA_READ_APPRAISED 0x00080000 +#define IMA_READ_APPRAISE 0x00004000 +#define IMA_READ_APPRAISED 0x00008000 #define IMA_APPRAISE_SUBMASK (IMA_FILE_APPRAISE | IMA_MMAP_APPRAISE | \ - IMA_BPRM_APPRAISE | IMA_MODULE_APPRAISE | \ - IMA_FIRMWARE_APPRAISE | IMA_READ_APPRAISE) + IMA_BPRM_APPRAISE | IMA_READ_APPRAISE) #define IMA_APPRAISED_SUBMASK (IMA_FILE_APPRAISED | IMA_MMAP_APPRAISED | \ - IMA_BPRM_APPRAISED | IMA_MODULE_APPRAISED | \ - IMA_FIRMWARE_APPRAISED | IMA_READ_APPRAISED) + IMA_BPRM_APPRAISED | IMA_READ_APPRAISED) enum evm_ima_xattr_type { IMA_XATTR_DIGEST = 0x01, @@ -111,8 +105,6 @@ struct integrity_iint_cache { enum integrity_status ima_file_status:4; enum integrity_status ima_mmap_status:4; enum integrity_status ima_bprm_status:4; - enum integrity_status ima_module_status:4; - enum integrity_status ima_firmware_status:4; enum integrity_status ima_read_status:4; enum integrity_status evm_status:4; struct ima_digest_data *ima_hash; -- cgit v1.2.3 From d9ddf077bb85b54200dfcb5f2edec4f0d6a7c2ca Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Thu, 14 Jan 2016 20:59:14 -0500 Subject: ima: support for kexec image and initramfs Add IMA policy support for measuring/appraising the kexec image and initramfs. Two new IMA policy identifiers KEXEC_KERNEL_CHECK and KEXEC_INITRAMFS_CHECK are defined. Example policy rules: measure func=KEXEC_KERNEL_CHECK appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig measure func=KEXEC_INITRAMFS_CHECK appraise func=KEXEC_INITRAMFS_CHECK appraise_type=imasig Moving the enumeration to the vfs layer simplified the patches, allowing the IMA changes, for the most part, to be separated from the other changes. Unfortunately, passing either a kernel_read_file_id or a ima_hooks enumeration within IMA is messy. Option 1: duplicate kernel_read_file enumeration in ima_hooks enum kernel_read_file_id { ... READING_KEXEC_IMAGE, READING_KEXEC_INITRAMFS, READING_MAX_ID enum ima_hooks { ... KEXEC_KERNEL_CHECK KEXEC_INITRAMFS_CHECK Option 2: define ima_hooks as extension of kernel_read_file eg: enum ima_hooks { FILE_CHECK = READING_MAX_ID, MMAP_CHECK, In order to pass both kernel_read_file_id and ima_hooks values, we would need to specify a struct containing a union. struct caller_id { union { enum ima_hooks func_id; enum kernel_read_file_id read_id; }; }; Option 3: incorportate the ima_hooks enumeration into kernel_read_file_id, perhaps changing the enumeration name. For now, duplicate the new READING_KEXEC_IMAGE/INITRAMFS in the ima_hooks. Changelog v4: - replaced switch statement with a kernel_read_file_id to an ima_hooks id mapping array - Dmitry - renamed ima_hook tokens KEXEC_CHECK and INITRAMFS_CHECK to KEXEC_KERNEL_CHECK and KEXEC_INITRAMFS_CHECK respectively - Dave Young Signed-off-by: Mimi Zohar Acked-by: Petko Manolov Acked-by: Dmitry Kasatkin Cc: Dave Young --- Documentation/ABI/testing/ima_policy | 1 + security/integrity/ima/ima.h | 2 ++ security/integrity/ima/ima_main.c | 15 +++++++++------ security/integrity/ima/ima_policy.c | 17 ++++++++++++++++- 4 files changed, 28 insertions(+), 7 deletions(-) (limited to 'security') diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy index 0a378a88217a..bb0f9a135e21 100644 --- a/Documentation/ABI/testing/ima_policy +++ b/Documentation/ABI/testing/ima_policy @@ -27,6 +27,7 @@ Description: base: func:= [BPRM_CHECK][MMAP_CHECK][FILE_CHECK][MODULE_CHECK] [FIRMWARE_CHECK] + [KEXEC_KERNEL_CHECK] [KEXEC_INITRAMFS_CHECK] mask:= [[^]MAY_READ] [[^]MAY_WRITE] [[^]MAY_APPEND] [[^]MAY_EXEC] fsmagic:= hex value diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index a5d25921ee3c..bd97e0d290de 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -147,6 +147,8 @@ enum ima_hooks { POST_SETATTR, MODULE_CHECK, FIRMWARE_CHECK, + KEXEC_KERNEL_CHECK, + KEXEC_INITRAMFS_CHECK, MAX_CHECK }; diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 5da0b9c00072..f76488162c1e 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -339,6 +339,13 @@ int ima_read_file(struct file *file, enum kernel_read_file_id read_id) return 0; } +static int read_idmap[READING_MAX_ID] = { + [READING_FIRMWARE] = FIRMWARE_CHECK, + [READING_MODULE] = MODULE_CHECK, + [READING_KEXEC_IMAGE] = KEXEC_KERNEL_CHECK, + [READING_KEXEC_INITRAMFS] = KEXEC_INITRAMFS_CHECK, +}; + /** * ima_post_read_file - in memory collect/appraise/audit measurement * @file: pointer to the file to be measured/appraised/audit @@ -355,7 +362,7 @@ int ima_read_file(struct file *file, enum kernel_read_file_id read_id) int ima_post_read_file(struct file *file, void *buf, loff_t size, enum kernel_read_file_id read_id) { - enum ima_hooks func = FILE_CHECK; + enum ima_hooks func; if (!file && read_id == READING_FIRMWARE) { if ((ima_appraise & IMA_APPRAISE_FIRMWARE) && @@ -373,11 +380,7 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size, return 0; } - if (read_id == READING_FIRMWARE) - func = FIRMWARE_CHECK; - else if (read_id == READING_MODULE) - func = MODULE_CHECK; - + func = read_idmap[read_id] ?: FILE_CHECK; return process_measurement(file, buf, size, MAY_READ, func, 0); } diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 7571ce8841ff..646134cdf3e8 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -612,6 +612,12 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) entry->func = MMAP_CHECK; else if (strcmp(args[0].from, "BPRM_CHECK") == 0) entry->func = BPRM_CHECK; + else if (strcmp(args[0].from, "KEXEC_KERNEL_CHECK") == + 0) + entry->func = KEXEC_KERNEL_CHECK; + else if (strcmp(args[0].from, "KEXEC_INITRAMFS_CHECK") + == 0) + entry->func = KEXEC_INITRAMFS_CHECK; else result = -EINVAL; if (!result) @@ -855,7 +861,8 @@ static char *mask_tokens[] = { enum { func_file = 0, func_mmap, func_bprm, - func_module, func_firmware, func_post + func_module, func_firmware, func_post, + func_kexec_kernel, func_kexec_initramfs }; static char *func_tokens[] = { @@ -864,6 +871,8 @@ static char *func_tokens[] = { "BPRM_CHECK", "MODULE_CHECK", "FIRMWARE_CHECK", + "KEXEC_KERNEL_CHECK", + "KEXEC_INITRAMFS_CHECK", "POST_SETATTR" }; @@ -929,6 +938,12 @@ static void policy_func_show(struct seq_file *m, enum ima_hooks func) case POST_SETATTR: seq_printf(m, pt(Opt_func), ft(func_post)); break; + case KEXEC_KERNEL_CHECK: + seq_printf(m, pt(Opt_func), ft(func_kexec_kernel)); + break; + case KEXEC_INITRAMFS_CHECK: + seq_printf(m, pt(Opt_func), ft(func_kexec_initramfs)); + break; default: snprintf(tbuf, sizeof(tbuf), "%d", func); seq_printf(m, pt(Opt_func), tbuf); -- cgit v1.2.3 From 7429b092811fb20c6a5b261c2c116a6a90cb9a29 Mon Sep 17 00:00:00 2001 From: Dmitry Kasatkin Date: Fri, 11 Apr 2014 17:47:01 +0300 Subject: ima: load policy using path We currently cannot do appraisal or signature vetting of IMA policies since we currently can only load IMA policies by writing the contents of the policy directly in, as follows: cat policy-file > /ima/policy If we provide the kernel the path to the IMA policy so it can load the policy itself it'd be able to later appraise or vet the file signature if it has one. This patch adds support to load the IMA policy with a given path as follows: echo /etc/ima/ima_policy > /sys/kernel/security/ima/policy Changelog v4+: - moved kernel_read_file_from_path() error messages to callers v3: - moved kernel_read_file_from_path() to a separate patch v2: - after re-ordering the patches, replace calling integrity_kernel_read() to read the file with kernel_read_file_from_path() (Mimi) - Patch description re-written by Luis R. Rodriguez Signed-off-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar --- include/linux/fs.h | 1 + security/integrity/ima/ima_fs.c | 45 +++++++++++++++++++++++++++++++++++++++-- 2 files changed, 44 insertions(+), 2 deletions(-) (limited to 'security') diff --git a/include/linux/fs.h b/include/linux/fs.h index 52567252288e..e514f76db04f 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2581,6 +2581,7 @@ enum kernel_read_file_id { READING_MODULE, READING_KEXEC_IMAGE, READING_KEXEC_INITRAMFS, + READING_POLICY, READING_MAX_ID }; diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c index f355231997b4..a6c61b351f36 100644 --- a/security/integrity/ima/ima_fs.c +++ b/security/integrity/ima/ima_fs.c @@ -22,6 +22,7 @@ #include #include #include +#include #include "ima.h" @@ -258,6 +259,43 @@ static const struct file_operations ima_ascii_measurements_ops = { .release = seq_release, }; +static ssize_t ima_read_policy(char *path) +{ + void *data; + char *datap; + loff_t size; + int rc, pathlen = strlen(path); + + char *p; + + /* remove \n */ + datap = path; + strsep(&datap, "\n"); + + rc = kernel_read_file_from_path(path, &data, &size, 0, READING_POLICY); + if (rc < 0) { + pr_err("Unable to open file: %s (%d)", path, rc); + return rc; + } + + datap = data; + while (size > 0 && (p = strsep(&datap, "\n"))) { + pr_debug("rule: %s\n", p); + rc = ima_parse_add_rule(p); + if (rc < 0) + break; + size -= rc; + } + + vfree(data); + if (rc < 0) + return rc; + else if (size) + return -EINVAL; + else + return pathlen; +} + static ssize_t ima_write_policy(struct file *file, const char __user *buf, size_t datalen, loff_t *ppos) { @@ -286,9 +324,12 @@ static ssize_t ima_write_policy(struct file *file, const char __user *buf, result = mutex_lock_interruptible(&ima_write_mutex); if (result < 0) goto out_free; - result = ima_parse_add_rule(data); - mutex_unlock(&ima_write_mutex); + if (data[0] == '/') + result = ima_read_policy(data); + else + result = ima_parse_add_rule(data); + mutex_unlock(&ima_write_mutex); out_free: kfree(data); out: -- cgit v1.2.3 From 19f8a84713edc1d27ea05be00effb97b8f1ef207 Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Fri, 15 Jan 2016 10:17:12 -0500 Subject: ima: measure and appraise the IMA policy itself Add support for measuring and appraising the IMA policy itself. Changelog v4: - use braces on both if/else branches, even if single line on one of the branches - Dmitry - Use the id mapping - Dmitry Signed-off-by: Mimi Zohar Acked-by: Petko Manolov Acked-by: Dmitry Kasatkin --- security/integrity/ima/ima.h | 2 ++ security/integrity/ima/ima_fs.c | 12 ++++++++++-- security/integrity/ima/ima_main.c | 1 + security/integrity/ima/ima_policy.c | 12 +++++++++++- 4 files changed, 24 insertions(+), 3 deletions(-) (limited to 'security') diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index bd97e0d290de..5d0f61163d98 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -149,6 +149,7 @@ enum ima_hooks { FIRMWARE_CHECK, KEXEC_KERNEL_CHECK, KEXEC_INITRAMFS_CHECK, + POLICY_CHECK, MAX_CHECK }; @@ -191,6 +192,7 @@ int ima_policy_show(struct seq_file *m, void *v); #define IMA_APPRAISE_LOG 0x04 #define IMA_APPRAISE_MODULES 0x08 #define IMA_APPRAISE_FIRMWARE 0x10 +#define IMA_APPRAISE_POLICY 0x20 #ifdef CONFIG_IMA_APPRAISE int ima_appraise_measurement(enum ima_hooks func, diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c index a6c61b351f36..60d011aaec38 100644 --- a/security/integrity/ima/ima_fs.c +++ b/security/integrity/ima/ima_fs.c @@ -325,10 +325,18 @@ static ssize_t ima_write_policy(struct file *file, const char __user *buf, if (result < 0) goto out_free; - if (data[0] == '/') + if (data[0] == '/') { result = ima_read_policy(data); - else + } else if (ima_appraise & IMA_APPRAISE_POLICY) { + pr_err("IMA: signed policy file (specified as an absolute pathname) required\n"); + integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL, NULL, + "policy_update", "signed policy required", + 1, 0); + if (ima_appraise & IMA_APPRAISE_ENFORCE) + result = -EACCES; + } else { result = ima_parse_add_rule(data); + } mutex_unlock(&ima_write_mutex); out_free: kfree(data); diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index f76488162c1e..391f41751021 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -344,6 +344,7 @@ static int read_idmap[READING_MAX_ID] = { [READING_MODULE] = MODULE_CHECK, [READING_KEXEC_IMAGE] = KEXEC_KERNEL_CHECK, [READING_KEXEC_INITRAMFS] = KEXEC_INITRAMFS_CHECK, + [READING_POLICY] = POLICY_CHECK }; /** diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 646134cdf3e8..c1b5d00fe5d4 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -114,6 +114,7 @@ static struct ima_rule_entry default_measurement_rules[] = { .uid = GLOBAL_ROOT_UID, .flags = IMA_FUNC | IMA_INMASK | IMA_UID}, {.action = MEASURE, .func = MODULE_CHECK, .flags = IMA_FUNC}, {.action = MEASURE, .func = FIRMWARE_CHECK, .flags = IMA_FUNC}, + {.action = MEASURE, .func = POLICY_CHECK, .flags = IMA_FUNC}, }; static struct ima_rule_entry default_appraise_rules[] = { @@ -618,6 +619,8 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) else if (strcmp(args[0].from, "KEXEC_INITRAMFS_CHECK") == 0) entry->func = KEXEC_INITRAMFS_CHECK; + else if (strcmp(args[0].from, "POLICY_CHECK") == 0) + entry->func = POLICY_CHECK; else result = -EINVAL; if (!result) @@ -776,6 +779,8 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) temp_ima_appraise |= IMA_APPRAISE_MODULES; else if (entry->func == FIRMWARE_CHECK) temp_ima_appraise |= IMA_APPRAISE_FIRMWARE; + else if (entry->func == POLICY_CHECK) + temp_ima_appraise |= IMA_APPRAISE_POLICY; audit_log_format(ab, "res=%d", !result); audit_log_end(ab); return result; @@ -862,7 +867,8 @@ static char *mask_tokens[] = { enum { func_file = 0, func_mmap, func_bprm, func_module, func_firmware, func_post, - func_kexec_kernel, func_kexec_initramfs + func_kexec_kernel, func_kexec_initramfs, + func_policy }; static char *func_tokens[] = { @@ -873,6 +879,7 @@ static char *func_tokens[] = { "FIRMWARE_CHECK", "KEXEC_KERNEL_CHECK", "KEXEC_INITRAMFS_CHECK", + "POLICY_CHECK", "POST_SETATTR" }; @@ -944,6 +951,9 @@ static void policy_func_show(struct seq_file *m, enum ima_hooks func) case KEXEC_INITRAMFS_CHECK: seq_printf(m, pt(Opt_func), ft(func_kexec_initramfs)); break; + case POLICY_CHECK: + seq_printf(m, pt(Opt_func), ft(func_policy)); + break; default: snprintf(tbuf, sizeof(tbuf), "%d", func); seq_printf(m, pt(Opt_func), tbuf); -- cgit v1.2.3 From 95ee08fa373b9ede1059c2f384cfeafe10dcd6bb Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Mon, 7 Dec 2015 15:08:01 -0500 Subject: ima: require signed IMA policy Require the IMA policy to be signed when additional rules can be added. v1: - initialize the policy flag - include IMA_APPRAISE_POLICY in the policy flag Signed-off-by: Mimi Zohar Acked-by: Petko Manolov Acked-by: Dmitry Kasatkin --- security/integrity/ima/ima_policy.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'security') diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index c1b5d00fe5d4..be09e2cacf82 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -129,6 +129,10 @@ static struct ima_rule_entry default_appraise_rules[] = { {.action = DONT_APPRAISE, .fsmagic = SELINUX_MAGIC, .flags = IMA_FSMAGIC}, {.action = DONT_APPRAISE, .fsmagic = NSFS_MAGIC, .flags = IMA_FSMAGIC}, {.action = DONT_APPRAISE, .fsmagic = CGROUP_SUPER_MAGIC, .flags = IMA_FSMAGIC}, +#ifdef CONFIG_IMA_WRITE_POLICY + {.action = APPRAISE, .func = POLICY_CHECK, + .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED}, +#endif #ifndef CONFIG_IMA_APPRAISE_SIGNED_INIT {.action = APPRAISE, .fowner = GLOBAL_ROOT_UID, .flags = IMA_FOWNER}, #else @@ -412,9 +416,12 @@ void __init ima_init_policy(void) for (i = 0; i < appraise_entries; i++) { list_add_tail(&default_appraise_rules[i].list, &ima_default_rules); + if (default_appraise_rules[i].func == POLICY_CHECK) + temp_ima_appraise |= IMA_APPRAISE_POLICY; } ima_rules = &ima_default_rules; + ima_update_policy_flag(); } /* Make sure we have a valid policy, at least containing some rules. */ -- cgit v1.2.3