summaryrefslogtreecommitdiffstats
path: root/security/smack
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2015-04-15 11:08:27 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-04-15 11:08:27 -0700
commitd488d3a4ce08e96dad5cb3b6117517d57ccec98f (patch)
tree169b09c589e38f6d5f2ea0a9e25c6a9fb3ebf783 /security/smack
parentcb906953d2c3fd450655d9fa833f03690ad50c23 (diff)
parent5deeb5cece3f9b30c8129786726b9d02c412c8ca (diff)
downloadlinux-d488d3a4ce08e96dad5cb3b6117517d57ccec98f.tar.bz2
Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates from James Morris: "Highlights for this window: - improved AVC hashing for SELinux by John Brooks and Stephen Smalley - addition of an unconfined label to Smack - Smack documentation update - TPM driver updates" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (28 commits) lsm: copy comm before calling audit_log to avoid race in string printing tomoyo: Do not generate empty policy files tomoyo: Use if_changed when generating builtin-policy.h tomoyo: Use bin2c to generate builtin-policy.h selinux: increase avtab max buckets selinux: Use a better hash function for avtab selinux: convert avtab hash table to flex_array selinux: reconcile security_netlbl_secattr_to_sid() and mls_import_netlbl_cat() selinux: remove unnecessary pointer reassignment Smack: Updates for Smack documentation tpm/st33zp24/spi: Add missing device table for spi phy. tpm/st33zp24: Add proper wait for ordinal duration in case of irq mode smack: Fix gcc warning from unused smack_syslog_lock mutex in smackfs.c Smack: Allow an unconfined label in bringup mode Smack: getting the Smack security context of keys Smack: Assign smack_known_web as default smk_in label for kernel thread's socket tpm/tpm_infineon: Use struct dev_pm_ops for power management MAINTAINERS: Add Jason as designated reviewer for TPM tpm: Update KConfig text to include TPM2.0 FIFO chips tpm/st33zp24/dts/st33zp24-spi: Add dts documentation for st33zp24 spi phy ...
Diffstat (limited to 'security/smack')
-rw-r--r--security/smack/smack.h8
-rw-r--r--security/smack/smack_access.c43
-rw-r--r--security/smack/smack_lsm.c99
-rw-r--r--security/smack/smackfs.c97
4 files changed, 228 insertions, 19 deletions
diff --git a/security/smack/smack.h b/security/smack/smack.h
index 67ccb7b2b89b..49eada6266ec 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -105,6 +105,7 @@ struct task_smack {
#define SMK_INODE_INSTANT 0x01 /* inode is instantiated */
#define SMK_INODE_TRANSMUTE 0x02 /* directory is transmuting */
#define SMK_INODE_CHANGED 0x04 /* smack was transmuted */
+#define SMK_INODE_IMPURE 0x08 /* involved in an impure transaction */
/*
* A label access rule.
@@ -193,6 +194,10 @@ struct smk_port_label {
#define MAY_LOCK 0x00002000 /* Locks should be writes, but ... */
#define MAY_BRINGUP 0x00004000 /* Report use of this rule */
+#define SMACK_BRINGUP_ALLOW 1 /* Allow bringup mode */
+#define SMACK_UNCONFINED_SUBJECT 2 /* Allow unconfined label */
+#define SMACK_UNCONFINED_OBJECT 3 /* Allow unconfined label */
+
/*
* Just to make the common cases easier to deal with
*/
@@ -254,6 +259,9 @@ extern int smack_cipso_mapped;
extern struct smack_known *smack_net_ambient;
extern struct smack_known *smack_onlycap;
extern struct smack_known *smack_syslog_label;
+#ifdef CONFIG_SECURITY_SMACK_BRINGUP
+extern struct smack_known *smack_unconfined;
+#endif
extern struct smack_known smack_cipso_option;
extern int smack_ptrace_rule;
diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c
index 1158430f5bb9..0f410fc56e33 100644
--- a/security/smack/smack_access.c
+++ b/security/smack/smack_access.c
@@ -130,7 +130,8 @@ int smk_access(struct smack_known *subject, struct smack_known *object,
/*
* Hardcoded comparisons.
- *
+ */
+ /*
* A star subject can't access any object.
*/
if (subject == &smack_known_star) {
@@ -189,10 +190,20 @@ int smk_access(struct smack_known *subject, struct smack_known *object,
* succeed because of "b" rules.
*/
if (may & MAY_BRINGUP)
- rc = MAY_BRINGUP;
+ rc = SMACK_BRINGUP_ALLOW;
#endif
out_audit:
+
+#ifdef CONFIG_SECURITY_SMACK_BRINGUP
+ if (rc < 0) {
+ if (object == smack_unconfined)
+ rc = SMACK_UNCONFINED_OBJECT;
+ if (subject == smack_unconfined)
+ rc = SMACK_UNCONFINED_SUBJECT;
+ }
+#endif
+
#ifdef CONFIG_AUDIT
if (a)
smack_log(subject->smk_known, object->smk_known,
@@ -338,19 +349,16 @@ static void smack_log_callback(struct audit_buffer *ab, void *a)
void smack_log(char *subject_label, char *object_label, int request,
int result, struct smk_audit_info *ad)
{
+#ifdef CONFIG_SECURITY_SMACK_BRINGUP
+ char request_buffer[SMK_NUM_ACCESS_TYPE + 5];
+#else
char request_buffer[SMK_NUM_ACCESS_TYPE + 1];
+#endif
struct smack_audit_data *sad;
struct common_audit_data *a = &ad->a;
-#ifdef CONFIG_SECURITY_SMACK_BRINGUP
- /*
- * The result may be positive in bringup mode.
- */
- if (result > 0)
- result = 0;
-#endif
/* check if we have to log the current event */
- if (result != 0 && (log_policy & SMACK_AUDIT_DENIED) == 0)
+ if (result < 0 && (log_policy & SMACK_AUDIT_DENIED) == 0)
return;
if (result == 0 && (log_policy & SMACK_AUDIT_ACCEPT) == 0)
return;
@@ -364,6 +372,21 @@ void smack_log(char *subject_label, char *object_label, int request,
smack_str_from_perm(request_buffer, request);
sad->subject = subject_label;
sad->object = object_label;
+#ifdef CONFIG_SECURITY_SMACK_BRINGUP
+ /*
+ * The result may be positive in bringup mode.
+ * A positive result is an allow, but not for normal reasons.
+ * Mark it as successful, but don't filter it out even if
+ * the logging policy says to do so.
+ */
+ if (result == SMACK_UNCONFINED_SUBJECT)
+ strcat(request_buffer, "(US)");
+ else if (result == SMACK_UNCONFINED_OBJECT)
+ strcat(request_buffer, "(UO)");
+
+ if (result > 0)
+ result = 0;
+#endif
sad->request = request_buffer;
sad->result = result;
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 1511965549b8..69fdc384af30 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -57,6 +57,13 @@ static struct kmem_cache *smack_inode_cache;
int smack_enabled;
#ifdef CONFIG_SECURITY_SMACK_BRINGUP
+static char *smk_bu_mess[] = {
+ "Bringup Error", /* Unused */
+ "Bringup", /* SMACK_BRINGUP_ALLOW */
+ "Unconfined Subject", /* SMACK_UNCONFINED_SUBJECT */
+ "Unconfined Object", /* SMACK_UNCONFINED_OBJECT */
+};
+
static void smk_bu_mode(int mode, char *s)
{
int i = 0;
@@ -87,9 +94,11 @@ static int smk_bu_note(char *note, struct smack_known *sskp,
if (rc <= 0)
return rc;
+ if (rc > SMACK_UNCONFINED_OBJECT)
+ rc = 0;
smk_bu_mode(mode, acc);
- pr_info("Smack Bringup: (%s %s %s) %s\n",
+ pr_info("Smack %s: (%s %s %s) %s\n", smk_bu_mess[rc],
sskp->smk_known, oskp->smk_known, acc, note);
return 0;
}
@@ -106,9 +115,11 @@ static int smk_bu_current(char *note, struct smack_known *oskp,
if (rc <= 0)
return rc;
+ if (rc > SMACK_UNCONFINED_OBJECT)
+ rc = 0;
smk_bu_mode(mode, acc);
- pr_info("Smack Bringup: (%s %s %s) %s %s\n",
+ pr_info("Smack %s: (%s %s %s) %s %s\n", smk_bu_mess[rc],
tsp->smk_task->smk_known, oskp->smk_known,
acc, current->comm, note);
return 0;
@@ -126,9 +137,11 @@ static int smk_bu_task(struct task_struct *otp, int mode, int rc)
if (rc <= 0)
return rc;
+ if (rc > SMACK_UNCONFINED_OBJECT)
+ rc = 0;
smk_bu_mode(mode, acc);
- pr_info("Smack Bringup: (%s %s %s) %s to %s\n",
+ pr_info("Smack %s: (%s %s %s) %s to %s\n", smk_bu_mess[rc],
tsp->smk_task->smk_known, smk_task->smk_known, acc,
current->comm, otp->comm);
return 0;
@@ -141,14 +154,25 @@ static int smk_bu_task(struct task_struct *otp, int mode, int rc)
static int smk_bu_inode(struct inode *inode, int mode, int rc)
{
struct task_smack *tsp = current_security();
+ struct inode_smack *isp = inode->i_security;
char acc[SMK_NUM_ACCESS_TYPE + 1];
+ if (isp->smk_flags & SMK_INODE_IMPURE)
+ pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
+ inode->i_sb->s_id, inode->i_ino, current->comm);
+
if (rc <= 0)
return rc;
+ if (rc > SMACK_UNCONFINED_OBJECT)
+ rc = 0;
+ if (rc == SMACK_UNCONFINED_SUBJECT &&
+ (mode & (MAY_WRITE | MAY_APPEND)))
+ isp->smk_flags |= SMK_INODE_IMPURE;
smk_bu_mode(mode, acc);
- pr_info("Smack Bringup: (%s %s %s) inode=(%s %ld) %s\n",
- tsp->smk_task->smk_known, smk_of_inode(inode)->smk_known, acc,
+
+ pr_info("Smack %s: (%s %s %s) inode=(%s %ld) %s\n", smk_bu_mess[rc],
+ tsp->smk_task->smk_known, isp->smk_inode->smk_known, acc,
inode->i_sb->s_id, inode->i_ino, current->comm);
return 0;
}
@@ -162,13 +186,20 @@ static int smk_bu_file(struct file *file, int mode, int rc)
struct task_smack *tsp = current_security();
struct smack_known *sskp = tsp->smk_task;
struct inode *inode = file_inode(file);
+ struct inode_smack *isp = inode->i_security;
char acc[SMK_NUM_ACCESS_TYPE + 1];
+ if (isp->smk_flags & SMK_INODE_IMPURE)
+ pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
+ inode->i_sb->s_id, inode->i_ino, current->comm);
+
if (rc <= 0)
return rc;
+ if (rc > SMACK_UNCONFINED_OBJECT)
+ rc = 0;
smk_bu_mode(mode, acc);
- pr_info("Smack Bringup: (%s %s %s) file=(%s %ld %pD) %s\n",
+ pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc],
sskp->smk_known, smk_of_inode(inode)->smk_known, acc,
inode->i_sb->s_id, inode->i_ino, file,
current->comm);
@@ -185,13 +216,20 @@ static int smk_bu_credfile(const struct cred *cred, struct file *file,
struct task_smack *tsp = cred->security;
struct smack_known *sskp = tsp->smk_task;
struct inode *inode = file->f_inode;
+ struct inode_smack *isp = inode->i_security;
char acc[SMK_NUM_ACCESS_TYPE + 1];
+ if (isp->smk_flags & SMK_INODE_IMPURE)
+ pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
+ inode->i_sb->s_id, inode->i_ino, current->comm);
+
if (rc <= 0)
return rc;
+ if (rc > SMACK_UNCONFINED_OBJECT)
+ rc = 0;
smk_bu_mode(mode, acc);
- pr_info("Smack Bringup: (%s %s %s) file=(%s %ld %pD) %s\n",
+ pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc],
sskp->smk_known, smk_of_inode(inode)->smk_known, acc,
inode->i_sb->s_id, inode->i_ino, file,
current->comm);
@@ -2449,7 +2487,21 @@ static int smack_inode_setsecurity(struct inode *inode, const char *name,
static int smack_socket_post_create(struct socket *sock, int family,
int type, int protocol, int kern)
{
- if (family != PF_INET || sock->sk == NULL)
+ struct socket_smack *ssp;
+
+ if (sock->sk == NULL)
+ return 0;
+
+ /*
+ * Sockets created by kernel threads receive web label.
+ */
+ if (unlikely(current->flags & PF_KTHREAD)) {
+ ssp = sock->sk->sk_security;
+ ssp->smk_in = &smack_known_web;
+ ssp->smk_out = &smack_known_web;
+ }
+
+ if (family != PF_INET)
return 0;
/*
* Set the outbound netlbl.
@@ -3983,6 +4035,36 @@ static int smack_key_permission(key_ref_t key_ref,
rc = smk_bu_note("key access", tkp, keyp->security, request, rc);
return rc;
}
+
+/*
+ * smack_key_getsecurity - Smack label tagging the key
+ * @key points to the key to be queried
+ * @_buffer points to a pointer that should be set to point to the
+ * resulting string (if no label or an error occurs).
+ * Return the length of the string (including terminating NUL) or -ve if
+ * an error.
+ * May also return 0 (and a NULL buffer pointer) if there is no label.
+ */
+static int smack_key_getsecurity(struct key *key, char **_buffer)
+{
+ struct smack_known *skp = key->security;
+ size_t length;
+ char *copy;
+
+ if (key->security == NULL) {
+ *_buffer = NULL;
+ return 0;
+ }
+
+ copy = kstrdup(skp->smk_known, GFP_KERNEL);
+ if (copy == NULL)
+ return -ENOMEM;
+ length = strlen(copy) + 1;
+
+ *_buffer = copy;
+ return length;
+}
+
#endif /* CONFIG_KEYS */
/*
@@ -4307,6 +4389,7 @@ struct security_operations smack_ops = {
.key_alloc = smack_key_alloc,
.key_free = smack_key_free,
.key_permission = smack_key_permission,
+ .key_getsecurity = smack_key_getsecurity,
#endif /* CONFIG_KEYS */
/* Audit hooks */
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index bce4e8f1b267..06f719ed63c9 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -54,6 +54,9 @@ enum smk_inos {
SMK_CHANGE_RULE = 19, /* change or add rules (long labels) */
SMK_SYSLOG = 20, /* change syslog label) */
SMK_PTRACE = 21, /* set ptrace rule */
+#ifdef CONFIG_SECURITY_SMACK_BRINGUP
+ SMK_UNCONFINED = 22, /* define an unconfined label */
+#endif
};
/*
@@ -61,7 +64,6 @@ enum smk_inos {
*/
static DEFINE_MUTEX(smack_cipso_lock);
static DEFINE_MUTEX(smack_ambient_lock);
-static DEFINE_MUTEX(smack_syslog_lock);
static DEFINE_MUTEX(smk_netlbladdr_lock);
/*
@@ -95,6 +97,16 @@ int smack_cipso_mapped = SMACK_CIPSO_MAPPED_DEFAULT;
*/
struct smack_known *smack_onlycap;
+#ifdef CONFIG_SECURITY_SMACK_BRINGUP
+/*
+ * Allow one label to be unconfined. This is for
+ * debugging and application bring-up purposes only.
+ * It is bad and wrong, but everyone seems to expect
+ * to have it.
+ */
+struct smack_known *smack_unconfined;
+#endif
+
/*
* If this value is set restrict syslog use to the label specified.
* It can be reset via smackfs/syslog
@@ -1717,6 +1729,85 @@ static const struct file_operations smk_onlycap_ops = {
.llseek = default_llseek,
};
+#ifdef CONFIG_SECURITY_SMACK_BRINGUP
+/**
+ * smk_read_unconfined - read() for smackfs/unconfined
+ * @filp: file pointer, not actually used
+ * @buf: where to put the result
+ * @cn: maximum to send along
+ * @ppos: where to start
+ *
+ * Returns number of bytes read or error code, as appropriate
+ */
+static ssize_t smk_read_unconfined(struct file *filp, char __user *buf,
+ size_t cn, loff_t *ppos)
+{
+ char *smack = "";
+ ssize_t rc = -EINVAL;
+ int asize;
+
+ if (*ppos != 0)
+ return 0;
+
+ if (smack_unconfined != NULL)
+ smack = smack_unconfined->smk_known;
+
+ asize = strlen(smack) + 1;
+
+ if (cn >= asize)
+ rc = simple_read_from_buffer(buf, cn, ppos, smack, asize);
+
+ return rc;
+}
+
+/**
+ * smk_write_unconfined - write() for smackfs/unconfined
+ * @file: file pointer, not actually used
+ * @buf: where to get the data from
+ * @count: bytes sent
+ * @ppos: where to start
+ *
+ * Returns number of bytes written or error code, as appropriate
+ */
+static ssize_t smk_write_unconfined(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ char *data;
+ int rc = count;
+
+ if (!smack_privileged(CAP_MAC_ADMIN))
+ return -EPERM;
+
+ data = kzalloc(count + 1, GFP_KERNEL);
+ if (data == NULL)
+ return -ENOMEM;
+
+ /*
+ * Should the null string be passed in unset the unconfined value.
+ * This seems like something to be careful with as usually
+ * smk_import only expects to return NULL for errors. It
+ * is usually the case that a nullstring or "\n" would be
+ * bad to pass to smk_import but in fact this is useful here.
+ *
+ * smk_import will also reject a label beginning with '-',
+ * so "-confine" will also work.
+ */
+ if (copy_from_user(data, buf, count) != 0)
+ rc = -EFAULT;
+ else
+ smack_unconfined = smk_import_entry(data, count);
+
+ kfree(data);
+ return rc;
+}
+
+static const struct file_operations smk_unconfined_ops = {
+ .read = smk_read_unconfined,
+ .write = smk_write_unconfined,
+ .llseek = default_llseek,
+};
+#endif /* CONFIG_SECURITY_SMACK_BRINGUP */
+
/**
* smk_read_logging - read() for /smack/logging
* @filp: file pointer, not actually used
@@ -2384,6 +2475,10 @@ static int smk_fill_super(struct super_block *sb, void *data, int silent)
"syslog", &smk_syslog_ops, S_IRUGO|S_IWUSR},
[SMK_PTRACE] = {
"ptrace", &smk_ptrace_ops, S_IRUGO|S_IWUSR},
+#ifdef CONFIG_SECURITY_SMACK_BRINGUP
+ [SMK_UNCONFINED] = {
+ "unconfined", &smk_unconfined_ops, S_IRUGO|S_IWUSR},
+#endif
/* last one */
{""}
};