diff options
Diffstat (limited to 'security')
| -rw-r--r-- | security/integrity/ima/ima_appraise.c | 9 | ||||
| -rw-r--r-- | security/integrity/ima/ima_main.c | 39 | ||||
| -rw-r--r-- | security/selinux/hooks.c | 8 | ||||
| -rw-r--r-- | security/selinux/ss/mls.c | 24 | ||||
| -rw-r--r-- | security/selinux/ss/policydb.c | 108 | ||||
| -rw-r--r-- | security/selinux/ss/services.c | 28 |
6 files changed, 182 insertions, 34 deletions
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index 18d0d9154317..ced2e131b061 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -274,8 +274,13 @@ static int xattr_verify(enum ima_hooks func, struct ima_iint_cache *iint, } else { set_bit(IMA_DIGSIG, &iint->atomic_flags); } - if (xattr_len - sizeof(xattr_value->type) - hash_start >= - iint->ima_hash->length) + /* + * Use addition, not subtraction: sizeof() forces unsigned + * math and a short xattr_len would wrap around, bypassing + * this bounds check. + */ + if (xattr_len >= (int)sizeof(xattr_value->type) + hash_start + + (int)iint->ima_hash->length) /* * xattr length may be longer. md5 hash in previous * version occupied 20 bytes in xattr, instead of 16 diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 5cea53fc36df..ff52becc3031 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -687,6 +687,43 @@ static int ima_file_check(struct file *file, int mask) MAY_APPEND), FILE_CHECK, 0, false); } +/* + * ima_reset_action_flags - invalidate action flags after a content change + * @inode: inode of the file whose content is about to be truncated + * + * Clear IMA_DONE_MASK so the file is re-collected, re-measured, + * re-audited, and re-appraised on next access. + */ +static void ima_reset_action_flags(struct inode *inode) +{ + struct ima_iint_cache *iint; + + if (!ima_policy_flag || !S_ISREG(inode->i_mode)) + return; + + iint = ima_iint_find(inode); + if (!iint) + return; + + mutex_lock(&iint->mutex); + iint->flags &= ~IMA_DONE_MASK; + iint->measured_pcrs = 0; + mutex_unlock(&iint->mutex); + return; +} + +static int ima_path_truncate(const struct path *path) +{ + ima_reset_action_flags(path->dentry->d_inode); + return 0; +} + +static int ima_file_truncate(struct file *file) +{ + ima_reset_action_flags(file_inode(file)); + return 0; +} + static int __ima_inode_hash(struct inode *inode, struct file *file, char *buf, size_t buf_size) { @@ -1300,11 +1337,13 @@ static struct security_hook_list ima_hooks[] __ro_after_init = { LSM_HOOK_INIT(file_release, ima_file_free), LSM_HOOK_INIT(mmap_file, ima_file_mmap), LSM_HOOK_INIT(file_mprotect, ima_file_mprotect), + LSM_HOOK_INIT(file_truncate, ima_file_truncate), LSM_HOOK_INIT(kernel_load_data, ima_load_data), LSM_HOOK_INIT(kernel_post_load_data, ima_post_load_data), LSM_HOOK_INIT(kernel_read_file, ima_read_file), LSM_HOOK_INIT(kernel_post_read_file, ima_post_read_file), LSM_HOOK_INIT(path_post_mknod, ima_post_path_mknod), + LSM_HOOK_INIT(path_truncate, ima_path_truncate), #ifdef CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS LSM_HOOK_INIT(key_post_create_or_update, ima_post_key_create_or_update), #endif diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 8d6945edae7a..18dd28b2bb13 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2974,6 +2974,10 @@ static int selinux_inode_init_security(struct inode *inode, struct inode *dir, sbsec = selinux_superblock(dir->i_sb); + if (!selinux_initialized() || + !(sbsec->flags & SBLABEL_MNT)) + return -EOPNOTSUPP; + newsid = crsec->create_sid; newsclass = inode_mode_to_security_class(inode->i_mode); rc = selinux_determine_inode_label(crsec, dir, qstr, newsclass, &newsid); @@ -2988,10 +2992,6 @@ static int selinux_inode_init_security(struct inode *inode, struct inode *dir, isec->initialized = LABEL_INITIALIZED; } - if (!selinux_initialized() || - !(sbsec->flags & SBLABEL_MNT)) - return -EOPNOTSUPP; - xattr = lsm_get_xattr_slot(xattrs, xattr_count); if (xattr) { rc = security_sid_to_context_force(newsid, diff --git a/security/selinux/ss/mls.c b/security/selinux/ss/mls.c index 3cd36e2015fa..40c62600650e 100644 --- a/security/selinux/ss/mls.c +++ b/security/selinux/ss/mls.c @@ -160,9 +160,6 @@ bool mls_level_isvalid(const struct policydb *p, const struct mls_level *l) { const char *name; const struct level_datum *levdatum; - struct ebitmap_node *node; - u32 bit; - int rc; if (!l->sens || l->sens > p->p_levels.nprim) return false; @@ -176,21 +173,14 @@ bool mls_level_isvalid(const struct policydb *p, const struct mls_level *l) return false; /* - * Validate that all bits set in l->cat are also be set in - * levdatum->level->cat and no bit in l->cat is larger than - * p->p_cats.nprim. + * l is valid iff every bit in l->cat is set in levdatum->level.cat + * and no bit in l->cat is larger than p->p_cats.nprim. + * policydb_index() has already verified that every bit set in + * levdatum->level.cat names a defined category, so containment is + * sufficient here. */ - rc = ebitmap_contains(&levdatum->level.cat, &l->cat, - p->p_cats.nprim); - if (!rc) - return false; - - ebitmap_for_each_positive_bit(&levdatum->level.cat, node, bit) { - if (!sym_name(p, SYM_CATS, bit)) - return false; - } - - return true; + return ebitmap_contains(&levdatum->level.cat, &l->cat, + p->p_cats.nprim); } bool mls_range_isvalid(const struct policydb *p, const struct mls_range *r) diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c index ead504a639e3..8a32666c0ba2 100644 --- a/security/selinux/ss/policydb.c +++ b/security/selinux/ss/policydb.c @@ -665,6 +665,23 @@ static int cat_index(void *key, void *datum, void *datap) return 0; } +static int sens_cat_index_check(void *key, void *datum, void *datap) +{ + struct policydb *p = datap; + struct level_datum *levdatum = datum; + struct ebitmap_node *node; + u32 bit; + + ebitmap_for_each_positive_bit(&levdatum->level.cat, node, bit) { + if (bit >= p->p_cats.nprim || !sym_name(p, SYM_CATS, bit)) { + pr_err("SELinux: sensitivity %s allows undefined category %u\n", + (const char *)key, bit + 1); + return -EINVAL; + } + } + return 0; +} + /* clang-format off */ static int (*const index_f[SYM_NUM])(void *key, void *datum, void *datap) = { common_index, @@ -719,6 +736,7 @@ static inline void symtab_hash_eval(struct symtab *s) static int policydb_index(struct policydb *p) { int i, rc; + u32 v; if (p->mls_enabled) pr_debug( @@ -769,6 +787,30 @@ static int policydb_index(struct policydb *p) if (rc) goto out; } + + /* + * A sparse class value is absorbed by policydb_class_isvalid() and + * its siblings, but no such predicate exists for booleans: every + * user of bool_val_to_struct[] walks it by index and dereferences + * each entry -- cond_evaluate_expr(), the two getters and + * security_set_bools() -- so an unclaimed one has no consumer that + * can tolerate it. + */ + for (v = 0; v < p->p_bools.nprim; v++) { + if (!p->bool_val_to_struct[v]) { + pr_err("SELinux: boolean %u is declared but not defined\n", + v + 1); + rc = -EINVAL; + goto out; + } + } + + if (p->mls_enabled) { + rc = hashtab_map(&p->p_levels.table, sens_cat_index_check, p); + if (rc) + goto out; + } + rc = 0; out: return rc; @@ -1154,7 +1196,18 @@ int str_read(char **strp, gfp_t flags, struct policy_file *fp, u32 len) return 0; } -static int perm_read(struct policydb *p, struct symtab *s, struct policy_file *fp) +/* + * Bitmap of the permission values a symtab has claimed. Values are 1-based + * and bounded by SEL_VEC_MAX, the width of an access vector, so the whole set + * fits in a u32 and the callers reject an nprim past that width. + */ +static u32 perm_claimed_mask(u32 nprim) +{ + return nprim ? U32_MAX >> (SEL_VEC_MAX - nprim) : 0; +} + +static int perm_read(struct policydb *p, struct symtab *s, + struct policy_file *fp, u32 *claimed) { char *key = NULL; struct perm_datum *perdatum; @@ -1175,6 +1228,13 @@ static int perm_read(struct policydb *p, struct symtab *s, struct policy_file *f rc = -EINVAL; if (perdatum->value < 1 || perdatum->value > SEL_VEC_MAX) goto bad; + /* indexes an nprim-sized array in security_get_permissions() */ + if (perdatum->value > s->nprim) + goto bad; + /* two permissions cannot share one slot of that array */ + if (*claimed & (1U << (perdatum->value - 1))) + goto bad; + *claimed |= 1U << (perdatum->value - 1); rc = str_read(&key, GFP_KERNEL, fp, len); if (rc) @@ -1195,7 +1255,7 @@ static int common_read(struct policydb *p, struct symtab *s, struct policy_file char *key = NULL; struct common_datum *comdatum; __le32 buf[4]; - u32 i, len, nel; + u32 i, len, nel, claimed = 0; int rc; comdatum = kzalloc_obj(*comdatum); @@ -1222,17 +1282,28 @@ static int common_read(struct policydb *p, struct symtab *s, struct policy_file if (rc) goto bad; comdatum->permissions.nprim = le32_to_cpu(buf[2]); + /* no permission value can reach a slot past SEL_VEC_MAX */ + rc = -EINVAL; + if (comdatum->permissions.nprim > SEL_VEC_MAX) + goto bad; rc = str_read(&key, GFP_KERNEL, fp, len); if (rc) goto bad; for (i = 0; i < nel; i++) { - rc = perm_read(p, &comdatum->permissions, fp); + rc = perm_read(p, &comdatum->permissions, fp, &claimed); if (rc) goto bad; } + rc = -EINVAL; + if (claimed != perm_claimed_mask(comdatum->permissions.nprim)) { + pr_err("SELinux: common %s does not define every permission it declares\n", + key); + goto bad; + } + hash_eval(&comdatum->permissions.table, "common_permissions", key); rc = symtab_insert(s, key, comdatum); @@ -1366,7 +1437,7 @@ static int class_read(struct policydb *p, struct symtab *s, struct policy_file * char *key = NULL; struct class_datum *cladatum; __le32 buf[6]; - u32 i, len, len2, ncons, nel, val; + u32 i, len, len2, ncons, nel, val, claimed = 0, inherited = 0; int rc; cladatum = kzalloc_obj(*cladatum); @@ -1399,6 +1470,10 @@ static int class_read(struct policydb *p, struct symtab *s, struct policy_file * if (rc) goto bad; cladatum->permissions.nprim = le32_to_cpu(buf[3]); + /* no permission value can reach a slot past SEL_VEC_MAX */ + rc = -EINVAL; + if (cladatum->permissions.nprim > SEL_VEC_MAX) + goto bad; ncons = le32_to_cpu(buf[5]); @@ -1419,13 +1494,36 @@ static int class_read(struct policydb *p, struct symtab *s, struct policy_file * cladatum->comkey); goto bad; } + + /* + * security_get_permissions() maps the common's permissions + * into an array sized by this class's nprim, so a class must + * declare at least as many as the common it inherits. + */ + if (cladatum->permissions.nprim < + cladatum->comdatum->permissions.nprim) { + pr_err("SELinux: class %s has fewer permissions than common %s\n", + key, cladatum->comkey); + goto bad; + } } for (i = 0; i < nel; i++) { - rc = perm_read(p, &cladatum->permissions, fp); + rc = perm_read(p, &cladatum->permissions, fp, &claimed); if (rc) goto bad; } + /* the class's own permissions must claim the slots the common leaves */ + if (cladatum->comdatum) + inherited = cladatum->comdatum->permissions.nprim; + rc = -EINVAL; + if (claimed != (perm_claimed_mask(cladatum->permissions.nprim) & + ~perm_claimed_mask(inherited))) { + pr_err("SELinux: class %s does not define every permission it declares\n", + key); + goto bad; + } + hash_eval(&cladatum->permissions.table, "class_permissions", key); rc = read_cons_helper(p, &cladatum->constraints, ncons, 0, fp); diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index 2d828548f3db..7afce975436e 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -2221,7 +2221,9 @@ void selinux_policy_cancel(struct selinux_load_state *load_state) oldpolicy = rcu_dereference_protected(state->policy, lockdep_is_held(&state->policy_mutex)); - sidtab_cancel_convert(oldpolicy->sidtab); + /* a first load has no outgoing policy and converted nothing */ + if (oldpolicy) + sidtab_cancel_convert(oldpolicy->sidtab); selinux_policy_free(load_state->policy); kfree(load_state->convert_data); } @@ -3302,6 +3304,7 @@ int security_get_classes(struct selinux_policy *policy, char ***classes, u32 *nclasses) { struct policydb *policydb; + u32 i; int rc; policydb = &policy->policydb; @@ -3314,16 +3317,29 @@ int security_get_classes(struct selinux_policy *policy, rc = hashtab_map(&policydb->p_classes.table, get_classes_callback, *classes); - if (rc) { - u32 i; + if (rc) + goto err; - for (i = 0; i < *nclasses; i++) - kfree((*classes)[i]); - kfree(*classes); + /* + * The class symtab may be sparse, which policydb_class_isvalid() exists + * to absorb; the callback fills this array by value, so an unclaimed + * one leaves a NULL that sel_make_classes() hands to sel_make_dir(). + */ + for (i = 0; i < *nclasses; i++) { + if (!(*classes)[i]) { + rc = -EINVAL; + goto err; + } } out: return rc; + +err: + for (i = 0; i < *nclasses; i++) + kfree((*classes)[i]); + kfree(*classes); + return rc; } static int get_permissions_callback(void *k, void *d, void *args) |