diff options
author | Jeff Vander Stoep <jeffv@google.com> | 2015-07-10 17:19:56 -0400 |
---|---|---|
committer | Paul Moore <pmoore@redhat.com> | 2015-07-13 13:31:58 -0400 |
commit | fa1aa143ac4a682c7f5fd52a3cf05f5a6fe44a0a (patch) | |
tree | 3f53aa6f35af83370aa7cd7bc25a2f6a2b6b8bbd /security/selinux/ss | |
parent | 671a2781ff01abf4fdc8904881fc3abd3a8279af (diff) | |
download | linux-fa1aa143ac4a682c7f5fd52a3cf05f5a6fe44a0a.tar.bz2 |
selinux: extended permissions for ioctls
Add extended permissions logic to selinux. Extended permissions
provides additional permissions in 256 bit increments. Extend the
generic ioctl permission check to use the extended permissions for
per-command filtering. Source/target/class sets including the ioctl
permission may additionally include a set of commands. Example:
allowxperm <source> <target>:<class> ioctl unpriv_app_socket_cmds
auditallowxperm <source> <target>:<class> ioctl priv_gpu_cmds
Where unpriv_app_socket_cmds and priv_gpu_cmds are macros
representing commonly granted sets of ioctl commands.
When ioctl commands are omitted only the permissions are checked.
This feature is intended to provide finer granularity for the ioctl
permission that may be too imprecise. For example, the same driver
may use ioctls to provide important and benign functionality such as
driver version or socket type as well as dangerous capabilities such
as debugging features, read/write/execute to physical memory or
access to sensitive data. Per-command filtering provides a mechanism
to reduce the attack surface of the kernel, and limit applications
to the subset of commands required.
The format of the policy binary has been modified to include ioctl
commands, and the policy version number has been incremented to
POLICYDB_VERSION_XPERMS_IOCTL=30 to account for the format
change.
The extended permissions logic is deliberately generic to allow
components to be reused e.g. netlink filters
Signed-off-by: Jeff Vander Stoep <jeffv@google.com>
Acked-by: Nick Kralevich <nnk@google.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Diffstat (limited to 'security/selinux/ss')
-rw-r--r-- | security/selinux/ss/avtab.c | 104 | ||||
-rw-r--r-- | security/selinux/ss/avtab.h | 33 | ||||
-rw-r--r-- | security/selinux/ss/conditional.c | 32 | ||||
-rw-r--r-- | security/selinux/ss/conditional.h | 6 | ||||
-rw-r--r-- | security/selinux/ss/policydb.c | 5 | ||||
-rw-r--r-- | security/selinux/ss/services.c | 213 | ||||
-rw-r--r-- | security/selinux/ss/services.h | 6 |
7 files changed, 357 insertions, 42 deletions
diff --git a/security/selinux/ss/avtab.c b/security/selinux/ss/avtab.c index b64f2772b030..3628d3a868b6 100644 --- a/security/selinux/ss/avtab.c +++ b/security/selinux/ss/avtab.c @@ -24,6 +24,7 @@ #include "policydb.h" static struct kmem_cache *avtab_node_cachep; +static struct kmem_cache *avtab_xperms_cachep; /* Based on MurmurHash3, written by Austin Appleby and placed in the * public domain. @@ -70,11 +71,24 @@ avtab_insert_node(struct avtab *h, int hvalue, struct avtab_key *key, struct avtab_datum *datum) { struct avtab_node *newnode; + struct avtab_extended_perms *xperms; newnode = kmem_cache_zalloc(avtab_node_cachep, GFP_KERNEL); if (newnode == NULL) return NULL; newnode->key = *key; - newnode->datum = *datum; + + if (key->specified & AVTAB_XPERMS) { + xperms = kmem_cache_zalloc(avtab_xperms_cachep, GFP_KERNEL); + if (xperms == NULL) { + kmem_cache_free(avtab_node_cachep, newnode); + return NULL; + } + *xperms = *(datum->u.xperms); + newnode->datum.u.xperms = xperms; + } else { + newnode->datum.u.data = datum->u.data; + } + if (prev) { newnode->next = prev->next; prev->next = newnode; @@ -107,8 +121,12 @@ static int avtab_insert(struct avtab *h, struct avtab_key *key, struct avtab_dat if (key->source_type == cur->key.source_type && key->target_type == cur->key.target_type && key->target_class == cur->key.target_class && - (specified & cur->key.specified)) + (specified & cur->key.specified)) { + /* extended perms may not be unique */ + if (specified & AVTAB_XPERMS) + break; return -EEXIST; + } if (key->source_type < cur->key.source_type) break; if (key->source_type == cur->key.source_type && @@ -271,6 +289,9 @@ void avtab_destroy(struct avtab *h) while (cur) { temp = cur; cur = cur->next; + if (temp->key.specified & AVTAB_XPERMS) + kmem_cache_free(avtab_xperms_cachep, + temp->datum.u.xperms); kmem_cache_free(avtab_node_cachep, temp); } } @@ -359,7 +380,10 @@ static uint16_t spec_order[] = { AVTAB_AUDITALLOW, AVTAB_TRANSITION, AVTAB_CHANGE, - AVTAB_MEMBER + AVTAB_MEMBER, + AVTAB_XPERMS_ALLOWED, + AVTAB_XPERMS_AUDITALLOW, + AVTAB_XPERMS_DONTAUDIT }; int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol, @@ -369,10 +393,11 @@ int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol, { __le16 buf16[4]; u16 enabled; - __le32 buf32[7]; u32 items, items2, val, vers = pol->policyvers; struct avtab_key key; struct avtab_datum datum; + struct avtab_extended_perms xperms; + __le32 buf32[ARRAY_SIZE(xperms.perms.p)]; int i, rc; unsigned set; @@ -429,11 +454,15 @@ int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol, printk(KERN_ERR "SELinux: avtab: entry has both access vectors and types\n"); return -EINVAL; } + if (val & AVTAB_XPERMS) { + printk(KERN_ERR "SELinux: avtab: entry has extended permissions\n"); + return -EINVAL; + } for (i = 0; i < ARRAY_SIZE(spec_order); i++) { if (val & spec_order[i]) { key.specified = spec_order[i] | enabled; - datum.data = le32_to_cpu(buf32[items++]); + datum.u.data = le32_to_cpu(buf32[items++]); rc = insertf(a, &key, &datum, p); if (rc) return rc; @@ -476,14 +505,42 @@ int avtab_read_item(struct avtab *a, void *fp, struct policydb *pol, return -EINVAL; } - rc = next_entry(buf32, fp, sizeof(u32)); - if (rc) { - printk(KERN_ERR "SELinux: avtab: truncated entry\n"); - return rc; + if ((vers < POLICYDB_VERSION_XPERMS_IOCTL) && + (key.specified & AVTAB_XPERMS)) { + printk(KERN_ERR "SELinux: avtab: policy version %u does not " + "support extended permissions rules and one " + "was specified\n", vers); + return -EINVAL; + } else if (key.specified & AVTAB_XPERMS) { + memset(&xperms, 0, sizeof(struct avtab_extended_perms)); + rc = next_entry(&xperms.specified, fp, sizeof(u8)); + if (rc) { + printk(KERN_ERR "SELinux: avtab: truncated entry\n"); + return rc; + } + rc = next_entry(&xperms.driver, fp, sizeof(u8)); + if (rc) { + printk(KERN_ERR "SELinux: avtab: truncated entry\n"); + return rc; + } + rc = next_entry(buf32, fp, sizeof(u32)*ARRAY_SIZE(xperms.perms.p)); + if (rc) { + printk(KERN_ERR "SELinux: avtab: truncated entry\n"); + return rc; + } + for (i = 0; i < ARRAY_SIZE(xperms.perms.p); i++) + xperms.perms.p[i] = le32_to_cpu(buf32[i]); + datum.u.xperms = &xperms; + } else { + rc = next_entry(buf32, fp, sizeof(u32)); + if (rc) { + printk(KERN_ERR "SELinux: avtab: truncated entry\n"); + return rc; + } + datum.u.data = le32_to_cpu(*buf32); } - datum.data = le32_to_cpu(*buf32); if ((key.specified & AVTAB_TYPE) && - !policydb_type_isvalid(pol, datum.data)) { + !policydb_type_isvalid(pol, datum.u.data)) { printk(KERN_ERR "SELinux: avtab: invalid type\n"); return -EINVAL; } @@ -543,8 +600,9 @@ bad: int avtab_write_item(struct policydb *p, struct avtab_node *cur, void *fp) { __le16 buf16[4]; - __le32 buf32[1]; + __le32 buf32[ARRAY_SIZE(cur->datum.u.xperms->perms.p)]; int rc; + unsigned int i; buf16[0] = cpu_to_le16(cur->key.source_type); buf16[1] = cpu_to_le16(cur->key.target_type); @@ -553,8 +611,22 @@ int avtab_write_item(struct policydb *p, struct avtab_node *cur, void *fp) rc = put_entry(buf16, sizeof(u16), 4, fp); if (rc) return rc; - buf32[0] = cpu_to_le32(cur->datum.data); - rc = put_entry(buf32, sizeof(u32), 1, fp); + + if (cur->key.specified & AVTAB_XPERMS) { + rc = put_entry(&cur->datum.u.xperms->specified, sizeof(u8), 1, fp); + if (rc) + return rc; + rc = put_entry(&cur->datum.u.xperms->driver, sizeof(u8), 1, fp); + if (rc) + return rc; + for (i = 0; i < ARRAY_SIZE(cur->datum.u.xperms->perms.p); i++) + buf32[i] = cpu_to_le32(cur->datum.u.xperms->perms.p[i]); + rc = put_entry(buf32, sizeof(u32), + ARRAY_SIZE(cur->datum.u.xperms->perms.p), fp); + } else { + buf32[0] = cpu_to_le32(cur->datum.u.data); + rc = put_entry(buf32, sizeof(u32), 1, fp); + } if (rc) return rc; return 0; @@ -588,9 +660,13 @@ void avtab_cache_init(void) avtab_node_cachep = kmem_cache_create("avtab_node", sizeof(struct avtab_node), 0, SLAB_PANIC, NULL); + avtab_xperms_cachep = kmem_cache_create("avtab_extended_perms", + sizeof(struct avtab_extended_perms), + 0, SLAB_PANIC, NULL); } void avtab_cache_destroy(void) { kmem_cache_destroy(avtab_node_cachep); + kmem_cache_destroy(avtab_xperms_cachep); } diff --git a/security/selinux/ss/avtab.h b/security/selinux/ss/avtab.h index adb451cd44f9..d946c9dc3c9c 100644 --- a/security/selinux/ss/avtab.h +++ b/security/selinux/ss/avtab.h @@ -23,6 +23,7 @@ #ifndef _SS_AVTAB_H_ #define _SS_AVTAB_H_ +#include "security.h" #include <linux/flex_array.h> struct avtab_key { @@ -37,13 +38,43 @@ struct avtab_key { #define AVTAB_MEMBER 0x0020 #define AVTAB_CHANGE 0x0040 #define AVTAB_TYPE (AVTAB_TRANSITION | AVTAB_MEMBER | AVTAB_CHANGE) +/* extended permissions */ +#define AVTAB_XPERMS_ALLOWED 0x0100 +#define AVTAB_XPERMS_AUDITALLOW 0x0200 +#define AVTAB_XPERMS_DONTAUDIT 0x0400 +#define AVTAB_XPERMS (AVTAB_XPERMS_ALLOWED | \ + AVTAB_XPERMS_AUDITALLOW | \ + AVTAB_XPERMS_DONTAUDIT) #define AVTAB_ENABLED_OLD 0x80000000 /* reserved for used in cond_avtab */ #define AVTAB_ENABLED 0x8000 /* reserved for used in cond_avtab */ u16 specified; /* what field is specified */ }; +/* + * For operations that require more than the 32 permissions provided by the avc + * extended permissions may be used to provide 256 bits of permissions. + */ +struct avtab_extended_perms { +/* These are not flags. All 256 values may be used */ +#define AVTAB_XPERMS_IOCTLFUNCTION 0x01 +#define AVTAB_XPERMS_IOCTLDRIVER 0x02 + /* extension of the avtab_key specified */ + u8 specified; /* ioctl, netfilter, ... */ + /* + * if 256 bits is not adequate as is often the case with ioctls, then + * multiple extended perms may be used and the driver field + * specifies which permissions are included. + */ + u8 driver; + /* 256 bits of permissions */ + struct extended_perms_data perms; +}; + struct avtab_datum { - u32 data; /* access vector or type value */ + union { + u32 data; /* access vector or type value */ + struct avtab_extended_perms *xperms; + } u; }; struct avtab_node { diff --git a/security/selinux/ss/conditional.c b/security/selinux/ss/conditional.c index 62c6773be0b7..18643bf9894d 100644 --- a/security/selinux/ss/conditional.c +++ b/security/selinux/ss/conditional.c @@ -15,6 +15,7 @@ #include "security.h" #include "conditional.h" +#include "services.h" /* * cond_evaluate_expr evaluates a conditional expr @@ -612,21 +613,39 @@ int cond_write_list(struct policydb *p, struct cond_node *list, void *fp) return 0; } + +void cond_compute_xperms(struct avtab *ctab, struct avtab_key *key, + struct extended_perms_decision *xpermd) +{ + struct avtab_node *node; + + if (!ctab || !key || !xpermd) + return; + + for (node = avtab_search_node(ctab, key); node; + node = avtab_search_node_next(node, key->specified)) { + if (node->key.specified & AVTAB_ENABLED) + services_compute_xperms_decision(xpermd, node); + } + return; + +} /* Determine whether additional permissions are granted by the conditional * av table, and if so, add them to the result */ -void cond_compute_av(struct avtab *ctab, struct avtab_key *key, struct av_decision *avd) +void cond_compute_av(struct avtab *ctab, struct avtab_key *key, + struct av_decision *avd, struct extended_perms *xperms) { struct avtab_node *node; - if (!ctab || !key || !avd) + if (!ctab || !key || !avd || !xperms) return; for (node = avtab_search_node(ctab, key); node; node = avtab_search_node_next(node, key->specified)) { if ((u16)(AVTAB_ALLOWED|AVTAB_ENABLED) == (node->key.specified & (AVTAB_ALLOWED|AVTAB_ENABLED))) - avd->allowed |= node->datum.data; + avd->allowed |= node->datum.u.data; if ((u16)(AVTAB_AUDITDENY|AVTAB_ENABLED) == (node->key.specified & (AVTAB_AUDITDENY|AVTAB_ENABLED))) /* Since a '0' in an auditdeny mask represents a @@ -634,10 +653,13 @@ void cond_compute_av(struct avtab *ctab, struct avtab_key *key, struct av_decisi * the '&' operand to ensure that all '0's in the mask * are retained (much unlike the allow and auditallow cases). */ - avd->auditdeny &= node->datum.data; + avd->auditdeny &= node->datum.u.data; if ((u16)(AVTAB_AUDITALLOW|AVTAB_ENABLED) == (node->key.specified & (AVTAB_AUDITALLOW|AVTAB_ENABLED))) - avd->auditallow |= node->datum.data; + avd->auditallow |= node->datum.u.data; + if ((node->key.specified & AVTAB_ENABLED) && + (node->key.specified & AVTAB_XPERMS)) + services_compute_xperms_drivers(xperms, node); } return; } diff --git a/security/selinux/ss/conditional.h b/security/selinux/ss/conditional.h index 4d1f87466508..ddb43e7e1c75 100644 --- a/security/selinux/ss/conditional.h +++ b/security/selinux/ss/conditional.h @@ -73,8 +73,10 @@ int cond_read_list(struct policydb *p, void *fp); int cond_write_bool(void *key, void *datum, void *ptr); int cond_write_list(struct policydb *p, struct cond_node *list, void *fp); -void cond_compute_av(struct avtab *ctab, struct avtab_key *key, struct av_decision *avd); - +void cond_compute_av(struct avtab *ctab, struct avtab_key *key, + struct av_decision *avd, struct extended_perms *xperms); +void cond_compute_xperms(struct avtab *ctab, struct avtab_key *key, + struct extended_perms_decision *xpermd); int evaluate_cond_node(struct policydb *p, struct cond_node *node); #endif /* _CONDITIONAL_H_ */ diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c index 74aa224267c1..992a31530825 100644 --- a/security/selinux/ss/policydb.c +++ b/security/selinux/ss/policydb.c @@ -148,6 +148,11 @@ static struct policydb_compat_info policydb_compat[] = { .sym_num = SYM_NUM, .ocon_num = OCON_NUM, }, + { + .version = POLICYDB_VERSION_XPERMS_IOCTL, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM, + }, }; static struct policydb_compat_info *policydb_lookup_compat(int version) diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index 9e2d82070915..b7df12ba61d8 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -93,9 +93,10 @@ static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len); static void context_struct_compute_av(struct context *scontext, - struct context *tcontext, - u16 tclass, - struct av_decision *avd); + struct context *tcontext, + u16 tclass, + struct av_decision *avd, + struct extended_perms *xperms); struct selinux_mapping { u16 value; /* policy value */ @@ -565,7 +566,8 @@ static void type_attribute_bounds_av(struct context *scontext, context_struct_compute_av(&lo_scontext, tcontext, tclass, - &lo_avd); + &lo_avd, + NULL); if ((lo_avd.allowed & avd->allowed) == avd->allowed) return; /* no masked permission */ masked = ~lo_avd.allowed & avd->allowed; @@ -580,7 +582,8 @@ static void type_attribute_bounds_av(struct context *scontext, context_struct_compute_av(scontext, &lo_tcontext, tclass, - &lo_avd); + &lo_avd, + NULL); if ((lo_avd.allowed & avd->allowed) == avd->allowed) return; /* no masked permission */ masked = ~lo_avd.allowed & avd->allowed; @@ -596,7 +599,8 @@ static void type_attribute_bounds_av(struct context *scontext, context_struct_compute_av(&lo_scontext, &lo_tcontext, tclass, - &lo_avd); + &lo_avd, + NULL); if ((lo_avd.allowed & avd->allowed) == avd->allowed) return; /* no masked permission */ masked = ~lo_avd.allowed & avd->allowed; @@ -613,13 +617,39 @@ static void type_attribute_bounds_av(struct context *scontext, } /* - * Compute access vectors based on a context structure pair for - * the permissions in a particular class. + * flag which drivers have permissions + * only looking for ioctl based extended permssions + */ +void services_compute_xperms_drivers( + struct extended_perms *xperms, + struct avtab_node *node) +{ + unsigned int i; + + if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { + /* if one or more driver has all permissions allowed */ + for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++) + xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i]; + } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { + /* if allowing permissions within a driver */ + security_xperm_set(xperms->drivers.p, + node->datum.u.xperms->driver); + } + + /* If no ioctl commands are allowed, ignore auditallow and auditdeny */ + if (node->key.specified & AVTAB_XPERMS_ALLOWED) + xperms->len = 1; +} + +/* + * Compute access vectors and extended permissions based on a context + * structure pair for the permissions in a particular class. */ static void context_struct_compute_av(struct context *scontext, - struct context *tcontext, - u16 tclass, - struct av_decision *avd) + struct context *tcontext, + u16 tclass, + struct av_decision *avd, + struct extended_perms *xperms) { struct constraint_node *constraint; struct role_allow *ra; @@ -633,6 +663,10 @@ static void context_struct_compute_av(struct context *scontext, avd->allowed = 0; avd->auditallow = 0; avd->auditdeny = 0xffffffff; + if (xperms) { + memset(&xperms->drivers, 0, sizeof(xperms->drivers)); + xperms->len = 0; + } if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) { if (printk_ratelimit()) @@ -647,7 +681,7 @@ static void context_struct_compute_av(struct context *scontext, * this permission check, then use it. */ avkey.target_class = tclass; - avkey.specified = AVTAB_AV; + avkey.specified = AVTAB_AV | AVTAB_XPERMS; sattr = flex_array_get(policydb.type_attr_map_array, scontext->type - 1); BUG_ON(!sattr); tattr = flex_array_get(policydb.type_attr_map_array, tcontext->type - 1); @@ -660,15 +694,18 @@ static void context_struct_compute_av(struct context *scontext, node; node = avtab_search_node_next(node, avkey.specified)) { if (node->key.specified == AVTAB_ALLOWED) - avd->allowed |= node->datum.data; + avd->allowed |= node->datum.u.data; else if (node->key.specified == AVTAB_AUDITALLOW) - avd->auditallow |= node->datum.data; + avd->auditallow |= node->datum.u.data; else if (node->key.specified == AVTAB_AUDITDENY) - avd->auditdeny &= node->datum.data; + avd->auditdeny &= node->datum.u.data; + else if (xperms && (node->key.specified & AVTAB_XPERMS)) + services_compute_xperms_drivers(xperms, node); } /* Check conditional av table for additional permissions */ - cond_compute_av(&policydb.te_cond_avtab, &avkey, avd); + cond_compute_av(&policydb.te_cond_avtab, &avkey, + avd, xperms); } } @@ -899,6 +936,139 @@ static void avd_init(struct av_decision *avd) avd->flags = 0; } +void services_compute_xperms_decision(struct extended_perms_decision *xpermd, + struct avtab_node *node) +{ + unsigned int i; + + if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { + if (xpermd->driver != node->datum.u.xperms->driver) + return; + } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { + if (!security_xperm_test(node->datum.u.xperms->perms.p, + xpermd->driver)) + return; + } else { + BUG(); + } + + if (node->key.specified == AVTAB_XPERMS_ALLOWED) { + xpermd->used |= XPERMS_ALLOWED; + if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { + memset(xpermd->allowed->p, 0xff, + sizeof(xpermd->allowed->p)); + } + if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { + for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++) + xpermd->allowed->p[i] |= + node->datum.u.xperms->perms.p[i]; + } + } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) { + xpermd->used |= XPERMS_AUDITALLOW; + if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { + memset(xpermd->auditallow->p, 0xff, + sizeof(xpermd->auditallow->p)); + } + if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { + for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++) + xpermd->auditallow->p[i] |= + node->datum.u.xperms->perms.p[i]; + } + } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) { + xpermd->used |= XPERMS_DONTAUDIT; + if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { + memset(xpermd->dontaudit->p, 0xff, + sizeof(xpermd->dontaudit->p)); + } + if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { + for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++) + xpermd->dontaudit->p[i] |= + node->datum.u.xperms->perms.p[i]; + } + } else { + BUG(); + } +} + +void security_compute_xperms_decision(u32 ssid, + u32 tsid, + u16 orig_tclass, + u8 driver, + struct extended_perms_decision *xpermd) +{ + u16 tclass; + struct context *scontext, *tcontext; + struct avtab_key avkey; + struct avtab_node *node; + struct ebitmap *sattr, *tattr; + struct ebitmap_node *snode, *tnode; + unsigned int i, j; + + xpermd->driver = driver; + xpermd->used = 0; + memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p)); + memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p)); + memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p)); + + read_lock(&policy_rwlock); + if (!ss_initialized) + goto allow; + + scontext = sidtab_search(&sidtab, ssid); + if (!scontext) { + printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", + __func__, ssid); + goto out; + } + + tcontext = sidtab_search(&sidtab, tsid); + if (!tcontext) { + printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", + __func__, tsid); + goto out; + } + + tclass = unmap_class(orig_tclass); + if (unlikely(orig_tclass && !tclass)) { + if (policydb.allow_unknown) + goto allow; + goto out; + } + + + if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) { + pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass); + goto out; + } + + avkey.target_class = tclass; + avkey.specified = AVTAB_XPERMS; + sattr = flex_array_get(policydb.type_attr_map_array, + scontext->type - 1); + BUG_ON(!sattr); + tattr = flex_array_get(policydb.type_attr_map_array, + tcontext->type - 1); + BUG_ON(!tattr); + ebitmap_for_each_positive_bit(sattr, snode, i) { + ebitmap_for_each_positive_bit(tattr, tnode, j) { + avkey.source_type = i + 1; + avkey.target_type = j + 1; + for (node = avtab_search_node(&policydb.te_avtab, &avkey); + node; + node = avtab_search_node_next(node, avkey.specified)) + services_compute_xperms_decision(xpermd, node); + + cond_compute_xperms(&policydb.te_cond_avtab, + &avkey, xpermd); + } + } +out: + read_unlock(&policy_rwlock); + return; +allow: + memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p)); + goto out; +} /** * security_compute_av - Compute access vector decisions. @@ -906,6 +1076,7 @@ static void avd_init(struct av_decision *avd) * @tsid: target security identifier * @tclass: target security class * @avd: access vector decisions + * @xperms: extended permissions * * Compute a set of access vector decisions based on the * SID pair (@ssid, @tsid) for the permissions in @tclass. @@ -913,13 +1084,15 @@ static void avd_init(struct av_decision *avd) void security_compute_av(u32 ssid, u32 tsid, u16 orig_tclass, - struct av_decision *avd) + struct av_decision *avd, + struct extended_perms *xperms) { u16 tclass; struct context *scontext = NULL, *tcontext = NULL; read_lock(&policy_rwlock); avd_init(avd); + xperms->len = 0; if (!ss_initialized) goto allow; @@ -947,7 +1120,7 @@ void security_compute_av(u32 ssid, goto allow; goto out; } - context_struct_compute_av(scontext, tcontext, tclass, avd); + context_struct_compute_av(scontext, tcontext, tclass, avd, xperms); map_decision(orig_tclass, avd, policydb.allow_unknown); out: read_unlock(&policy_rwlock); @@ -993,7 +1166,7 @@ void security_compute_av_user(u32 ssid, goto out; } - context_struct_compute_av(scontext, tcontext, tclass, avd); + context_struct_compute_av(scontext, tcontext, tclass, avd, NULL); out: read_unlock(&policy_rwlock); return; @@ -1515,7 +1688,7 @@ static int security_compute_sid(u32 ssid, if (avdatum) { /* Use the type from the type transition/member/change rule. */ - newcontext.type = avdatum->data; + newcontext.type = avdatum->u.data; } /* if we have a objname this is a file trans check so check those rules */ diff --git a/security/selinux/ss/services.h b/security/selinux/ss/services.h index e8d907e903cd..6abcd8729ec3 100644 --- a/security/selinux/ss/services.h +++ b/security/selinux/ss/services.h @@ -11,5 +11,11 @@ extern struct policydb policydb; +void services_compute_xperms_drivers(struct extended_perms *xperms, + struct avtab_node *node); + +void services_compute_xperms_decision(struct extended_perms_decision *xpermd, + struct avtab_node *node); + #endif /* _SS_SERVICES_H_ */ |