// SPDX-License-Identifier: GPL-2.0-only /* * AppArmor security module * * This file contains AppArmor functions for unpacking policy loaded from * userspace. * * Copyright (C) 1998-2008 Novell/SUSE * Copyright 2009-2010 Canonical Ltd. * * AppArmor uses a serialized binary format for loading policy. To find * policy format documentation see Documentation/admin-guide/LSM/apparmor.rst * All policy is validated before it is used. */ #include #include #include #include #include #include "include/apparmor.h" #include "include/audit.h" #include "include/cred.h" #include "include/crypto.h" #include "include/file.h" #include "include/match.h" #include "include/path.h" #include "include/policy.h" #include "include/policy_unpack.h" #include "include/policy_compat.h" /* audit callback for unpack fields */ static void audit_cb(struct audit_buffer *ab, void *va) { struct common_audit_data *sa = va; struct apparmor_audit_data *ad = aad(sa); if (ad->iface.ns) { audit_log_format(ab, " ns="); audit_log_untrustedstring(ab, ad->iface.ns); } if (ad->name) { audit_log_format(ab, " name="); audit_log_untrustedstring(ab, ad->name); } if (ad->iface.pos) audit_log_format(ab, " offset=%ld", ad->iface.pos); } /** * audit_iface - do audit message for policy unpacking/load/replace/remove * @new: profile if it has been allocated (MAYBE NULL) * @ns_name: name of the ns the profile is to be loaded to (MAY BE NULL) * @name: name of the profile being manipulated (MAYBE NULL) * @info: any extra info about the failure (MAYBE NULL) * @e: buffer position info * @error: error code * * Returns: %0 or error */ static int audit_iface(struct aa_profile *new, const char *ns_name, const char *name, const char *info, struct aa_ext *e, int error) { struct aa_profile *profile = labels_profile(aa_current_raw_label()); DEFINE_AUDIT_DATA(ad, LSM_AUDIT_DATA_NONE, AA_CLASS_NONE, NULL); if (e) ad.iface.pos = e->pos - e->start; ad.iface.ns = ns_name; if (new) ad.name = new->base.hname; else ad.name = name; ad.info = info; ad.error = error; return aa_audit(AUDIT_APPARMOR_STATUS, profile, &ad, audit_cb); } void __aa_loaddata_update(struct aa_loaddata *data, long revision) { AA_BUG(!data); AA_BUG(!data->ns); AA_BUG(!mutex_is_locked(&data->ns->lock)); AA_BUG(data->revision > revision); data->revision = revision; if ((data->dents[AAFS_LOADDATA_REVISION])) { struct inode *inode; inode = d_inode(data->dents[AAFS_LOADDATA_DIR]); inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode)); inode = d_inode(data->dents[AAFS_LOADDATA_REVISION]); inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode)); } } bool aa_rawdata_eq(struct aa_loaddata *l, struct aa_loaddata *r) { if (l->size != r->size) return false; if (l->compressed_size != r->compressed_size) return false; if (aa_g_hash_policy && memcmp(l->hash, r->hash, aa_hash_size()) != 0) return false; return memcmp(l->data, r->data, r->compressed_size ?: r->size) == 0; } /* * need to take the ns mutex lock which is NOT safe most places that * put_loaddata is called, so we have to delay freeing it */ static void do_loaddata_free(struct work_struct *work) { struct aa_loaddata *d = container_of(work, struct aa_loaddata, work); struct aa_ns *ns = aa_get_ns(d->ns); if (ns) { mutex_lock_nested(&ns->lock, ns->level); __aa_fs_remove_rawdata(d); mutex_unlock(&ns->lock); aa_put_ns(ns); } kfree_sensitive(d->hash); kfree_sensitive(d->name); kvfree(d->data); kfree_sensitive(d); } void aa_loaddata_kref(struct kref *kref) { struct aa_loaddata *d = container_of(kref, struct aa_loaddata, count); if (d) { INIT_WORK(&d->work, do_loaddata_free); schedule_work(&d->work); } } struct aa_loaddata *aa_loaddata_alloc(size_t size) { struct aa_loaddata *d; d = kzalloc(sizeof(*d), GFP_KERNEL); if (d == NULL) return ERR_PTR(-ENOMEM); d->data = kvzalloc(size, GFP_KERNEL); if (!d->data) { kfree(d); return ERR_PTR(-ENOMEM); } kref_init(&d->count); INIT_LIST_HEAD(&d->list); return d; } /* test if read will be in packed data bounds */ VISIBLE_IF_KUNIT bool aa_inbounds(struct aa_ext *e, size_t size) { return (size <= e->end - e->pos); } EXPORT_SYMBOL_IF_KUNIT(aa_inbounds); /** * aa_unpack_u16_chunk - test and do bounds checking for a u16 size based chunk * @e: serialized data read head (NOT NULL) * @chunk: start address for chunk of data (NOT NULL) * * Returns: the size of chunk found with the read head at the end of the chunk. */ VISIBLE_IF_KUNIT size_t aa_unpack_u16_chunk(struct aa_ext *e, char **chunk) { size_t size = 0; void *pos = e->pos; if (!aa_inbounds(e, sizeof(u16))) goto fail; size = le16_to_cpu(get_unaligned((__le16 *) e->pos)); e->pos += sizeof(__le16); if (!aa_inbounds(e, size)) goto fail; *chunk = e->pos; e->pos += size; return size; fail: e->pos = pos; return 0; } EXPORT_SYMBOL_IF_KUNIT(aa_unpack_u16_chunk); /* unpack control byte */ VISIBLE_IF_KUNIT bool aa_unpack_X(struct aa_ext *e, enum aa_code code) { if (!aa_inbounds(e, 1)) return false; if (*(u8 *) e->pos != code) return false; e->pos++; return true; } EXPORT_SYMBOL_IF_KUNIT(aa_unpack_X); /** * aa_unpack_nameX - check is the next element is of type X with a name of @name * @e: serialized data extent information (NOT NULL) * @code: type code * @name: name to match to the serialized element. (MAYBE NULL) * * check that the next serialized data element is of type X and has a tag * name @name. If @name is specified then there must be a matching * name element in the stream. If @name is NULL any name element will be * skipped and only the typecode will be tested. * * Returns true on success (both type code and name tests match) and the read * head is advanced past the headers * * Returns: false if either match fails, the read head does not move */ VISIBLE_IF_KUNIT bool aa_unpack_nameX(struct aa_ext *e, enum aa_code code, const char *name) { /* * May need to reset pos if name or type doesn't match */ void *pos = e->pos; /* * Check for presence of a tagname, and if present name size * AA_NAME tag value is a u16. */ if (aa_unpack_X(e, AA_NAME)) { char *tag = NULL; size_t size = aa_unpack_u16_chunk(e, &tag); /* if a name is specified it must match. otherwise skip tag */ if (name && (!size || tag[size-1] != '\0' || strcmp(name, tag))) goto fail; } else if (name) { /* if a name is specified and there is no name tag fail */ goto fail; } /* now check if type code matches */ if (aa_unpack_X(e, code)) return true; fail: e->pos = pos; return false; } EXPORT_SYMBOL_IF_KUNIT(aa_unpack_nameX); static bool unpack_u8(struct aa_ext *e, u8 *data, const char *name) { void *pos = e->pos; if (aa_unpack_nameX(e, AA_U8, name)) { if (!aa_inbounds(e, sizeof(u8))) goto fail; if (data) *data = *((u8 *)e->pos); e->pos += sizeof(u8); return true; } fail: e->pos = pos; return false; } VISIBLE_IF_KUNIT bool aa_unpack_u32(struct aa_ext *e, u32 *data, const char *name) { void *pos = e->pos; if (aa_unpack_nameX(e, AA_U32, name)) { if (!aa_inbounds(e, sizeof(u32))) goto fail; if (data) *data = le32_to_cpu(get_unaligned((__le32 *) e->pos)); e->pos += sizeof(u32); return true; } fail: e->pos = pos; return false; } EXPORT_SYMBOL_IF_KUNIT(aa_unpack_u32); VISIBLE_IF_KUNIT bool aa_unpack_u64(struct aa_ext *e, u64 *data, const char *name) { void *pos = e->pos; if (aa_unpack_nameX(e, AA_U64, name)) { if (!aa_inbounds(e, sizeof(u64))) goto fail; if (data) *data = le64_to_cpu(get_unaligned((__le64 *) e->pos)); e->pos += sizeof(u64); return true; } fail: e->pos = pos; return false; } EXPORT_SYMBOL_IF_KUNIT(aa_unpack_u64); static bool aa_unpack_cap_low(struct aa_ext *e, kernel_cap_t *data, const char *name) { u32 val; if (!aa_unpack_u32(e, &val, name)) return false; data->val = val; return true; } static bool aa_unpack_cap_high(struct aa_ext *e, kernel_cap_t *data, const char *name) { u32 val; if (!aa_unpack_u32(e, &val, name)) return false; data->val = (u32)data->val | ((u64)val << 32); return true; } VISIBLE_IF_KUNIT bool aa_unpack_array(struct aa_ext *e, const char *name, u16 *size) { void *pos = e->pos; if (aa_unpack_nameX(e, AA_ARRAY, name)) { if (!aa_inbounds(e, sizeof(u16))) goto fail; *size = le16_to_cpu(get_unaligned((__le16 *) e->pos)); e->pos += sizeof(u16); return true; } fail: e->pos = pos; return false; } EXPORT_SYMBOL_IF_KUNIT(aa_unpack_array); VISIBLE_IF_KUNIT size_t aa_unpack_blob(struct aa_ext *e, char **blob, const char *name) { void *pos = e->pos; if (aa_unpack_nameX(e, AA_BLOB, name)) { u32 size; if (!aa_inbounds(e, sizeof(u32))) goto fail; size = le32_to_cpu(get_unaligned((__le32 *) e->pos)); e->pos += sizeof(u32); if (aa_inbounds(e, (size_t) size)) { *blob = e->pos; e->pos += size; return size; } } fail: e->pos = pos; return 0; } EXPORT_SYMBOL_IF_KUNIT(aa_unpack_blob); VISIBLE_IF_KUNIT int aa_unpack_str(struct aa_ext *e, const char **string, const char *name) { char *src_str; size_t size = 0; void *pos = e->pos; *string = NULL; if (aa_unpack_nameX(e, AA_STRING, name)) { size = aa_unpack_u16_chunk(e, &src_str); if (size) { /* strings are null terminated, length is size - 1 */ if (src_str[size - 1] != 0) goto fail; *string = src_str; return size; } } fail: e->pos = pos; return 0; } EXPORT_SYMBOL_IF_KUNIT(aa_unpack_str); VISIBLE_IF_KUNIT int aa_unpack_strdup(struct aa_ext *e, char **string, const char *name) { const char *tmp; void *pos = e->pos; int res = aa_unpack_str(e, &tmp, name); *string = NULL; if (!res) return 0; *string = kmemdup(tmp, res, GFP_KERNEL); if (!*string) { e->pos = pos; return 0; } return res; } EXPORT_SYMBOL_IF_KUNIT(aa_unpack_strdup); /** * unpack_dfa - unpack a file rule dfa * @e: serialized data extent information (NOT NULL) * @flags: dfa flags to check * * returns dfa or ERR_PTR or NULL if no dfa */ static struct aa_dfa *unpack_dfa(struct aa_ext *e, int flags) { char *blob = NULL; size_t size; struct aa_dfa *dfa = NULL; size = aa_unpack_blob(e, &blob, "aadfa"); if (size) { /* * The dfa is aligned with in the blob to 8 bytes * from the beginning of the stream. * alignment adjust needed by dfa unpack */ size_t sz = blob - (char *) e->start - ((e->pos - e->start) & 7); size_t pad = ALIGN(sz, 8) - sz; if (aa_g_paranoid_load) flags |= DFA_FLAG_VERIFY_STATES; dfa = aa_dfa_unpack(blob + pad, size - pad, flags); if (IS_ERR(dfa)) return dfa; } return dfa; } /** * unpack_trans_table - unpack a profile transition table * @e: serialized data extent information (NOT NULL) * @strs: str table to unpack to (NOT NULL) * * Returns: true if table successfully unpacked or not present */ static bool unpack_trans_table(struct aa_ext *e, struct aa_str_table *strs) { void *saved_pos = e->pos; char **table = NULL; /* exec table is optional */ if (aa_unpack_nameX(e, AA_STRUCT, "xtable")) { u16 size; int i; if (!aa_unpack_array(e, NULL, &size)) /* * Note: index into trans table array is a max * of 2^24, but unpack array can only unpack * an array of 2^16 in size atm so no need * for size check here */ goto fail; table = kcalloc(size, sizeof(char *), GFP_KERNEL); if (!table) goto fail; strs->table = table; strs->size = size; for (i = 0; i < size; i++) { char *str; int c, j, pos, size2 = aa_unpack_strdup(e, &str, NULL); /* aa_unpack_strdup verifies that the last character is * null termination byte. */ if (!size2) goto fail; table[i] = str; /* verify that name doesn't start with space */ if (isspace(*str)) goto fail; /* count internal # of internal \0 */ for (c = j = 0; j < size2 - 1; j++) { if (!str[j]) { pos = j; c++; } } if (*str == ':') { /* first character after : must be valid */ if (!str[1]) goto fail; /* beginning with : requires an embedded \0, * verify that exactly 1 internal \0 exists * trailing \0 already verified by aa_unpack_strdup * * convert \0 back to : for label_parse */ if (c == 1) str[pos] = ':'; else if (c > 1) goto fail; } else if (c) /* fail - all other cases with embedded \0 */ goto fail; } if (!aa_unpack_nameX(e, AA_ARRAYEND, NULL)) goto fail; if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) goto fail; } return true; fail: aa_free_str_table(strs); e->pos = saved_pos; return false; } static bool unpack_xattrs(struct aa_ext *e, struct aa_profile *profile) { void *pos = e->pos; if (aa_unpack_nameX(e, AA_STRUCT, "xattrs")) { u16 size; int i; if (!aa_unpack_array(e, NULL, &size)) goto fail; profile->attach.xattr_count = size; profile->attach.xattrs = kcalloc(size, sizeof(char *), GFP_KERNEL); if (!profile->attach.xattrs) goto fail; for (i = 0; i < size; i++) { if (!aa_unpack_strdup(e, &profile->attach.xattrs[i], NULL)) goto fail; } if (!aa_unpack_nameX(e, AA_ARRAYEND, NULL)) goto fail; if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) goto fail; } return true; fail: e->pos = pos; return false; } static bool unpack_secmark(struct aa_ext *e, struct aa_ruleset *rules) { void *pos = e->pos; u16 size; int i; if (aa_unpack_nameX(e, AA_STRUCT, "secmark")) { if (!aa_unpack_array(e, NULL, &size)) goto fail; rules->secmark = kcalloc(size, sizeof(struct aa_secmark), GFP_KERNEL); if (!rules->secmark) goto fail; rules->secmark_count = size; for (i = 0; i < size; i++) { if (!unpack_u8(e, &rules->secmark[i].audit, NULL)) goto fail; if (!unpack_u8(e, &rules->secmark[i].deny, NULL)) goto fail; if (!aa_unpack_strdup(e, &rules->secmark[i].label, NULL)) goto fail; } if (!aa_unpack_nameX(e, AA_ARRAYEND, NULL)) goto fail; if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) goto fail; } return true; fail: if (rules->secmark) { for (i = 0; i < size; i++) kfree(rules->secmark[i].label); kfree(rules->secmark); rules->secmark_count = 0; rules->secmark = NULL; } e->pos = pos; return false; } static bool unpack_rlimits(struct aa_ext *e, struct aa_ruleset *rules) { void *pos = e->pos; /* rlimits are optional */ if (aa_unpack_nameX(e, AA_STRUCT, "rlimits")) { u16 size; int i; u32 tmp = 0; if (!aa_unpack_u32(e, &tmp, NULL)) goto fail; rules->rlimits.mask = tmp; if (!aa_unpack_array(e, NULL, &size) || size > RLIM_NLIMITS) goto fail; for (i = 0; i < size; i++) { u64 tmp2 = 0; int a = aa_map_resource(i); if (!aa_unpack_u64(e, &tmp2, NULL)) goto fail; rules->rlimits.limits[a].rlim_max = tmp2; } if (!aa_unpack_nameX(e, AA_ARRAYEND, NULL)) goto fail; if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) goto fail; } return true; fail: e->pos = pos; return false; } static bool unpack_perm(struct aa_ext *e, u32 version, struct aa_perms *perm) { if (version != 1) return false; return aa_unpack_u32(e, &perm->allow, NULL) && aa_unpack_u32(e, &perm->allow, NULL) && aa_unpack_u32(e, &perm->deny, NULL) && aa_unpack_u32(e, &perm->subtree, NULL) && aa_unpack_u32(e, &perm->cond, NULL) && aa_unpack_u32(e, &perm->kill, NULL) && aa_unpack_u32(e, &perm->complain, NULL) && aa_unpack_u32(e, &perm->prompt, NULL) && aa_unpack_u32(e, &perm->audit, NULL) && aa_unpack_u32(e, &perm->quiet, NULL) && aa_unpack_u32(e, &perm->hide, NULL) && aa_unpack_u32(e, &perm->xindex, NULL) && aa_unpack_u32(e, &perm->tag, NULL) && aa_unpack_u32(e, &perm->label, NULL); } static ssize_t unpack_perms_table(struct aa_ext *e, struct aa_perms **perms) { void *pos = e->pos; u16 size = 0; AA_BUG(!perms); /* * policy perms are optional, in which case perms are embedded * in the dfa accept table */ if (aa_unpack_nameX(e, AA_STRUCT, "perms")) { int i; u32 version; if (!aa_unpack_u32(e, &version, "version")) goto fail_reset; if (!aa_unpack_array(e, NULL, &size)) goto fail_reset; *perms = kcalloc(size, sizeof(struct aa_perms), GFP_KERNEL); if (!*perms) goto fail_reset; for (i = 0; i < size; i++) { if (!unpack_perm(e, version, &(*perms)[i])) goto fail; } if (!aa_unpack_nameX(e, AA_ARRAYEND, NULL)) goto fail; if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) goto fail; } else *perms = NULL; return size; fail: kfree(*perms); fail_reset: e->pos = pos; return -EPROTO; } static int unpack_pdb(struct aa_ext *e, struct aa_policydb **policy, bool required_dfa, bool required_trans, const char **info) { struct aa_policydb *pdb; void *pos = e->pos; int i, flags, error = -EPROTO; ssize_t size; pdb = aa_alloc_pdb(GFP_KERNEL); if (!pdb) return -ENOMEM; size = unpack_perms_table(e, &pdb->perms); if (size < 0) { error = size; pdb->perms = NULL; *info = "failed to unpack - perms"; goto fail; } pdb->size = size; if (pdb->perms) { /* perms table present accept is index */ flags = TO_ACCEPT1_FLAG(YYTD_DATA32); } else { /* packed perms in accept1 and accept2 */ flags = TO_ACCEPT1_FLAG(YYTD_DATA32) | TO_ACCEPT2_FLAG(YYTD_DATA32); } pdb->dfa = unpack_dfa(e, flags); if (IS_ERR(pdb->dfa)) { error = PTR_ERR(pdb->dfa); pdb->dfa = NULL; *info = "failed to unpack - dfa"; goto fail; } else if (!pdb->dfa) { if (required_dfa) { *info = "missing required dfa"; goto fail; } goto out; } /* * only unpack the following if a dfa is present * * sadly start was given different names for file and policydb * but since it is optional we can try both */ if (!aa_unpack_u32(e, &pdb->start[0], "start")) /* default start state */ pdb->start[0] = DFA_START; if (!aa_unpack_u32(e, &pdb->start[AA_CLASS_FILE], "dfa_start")) { /* default start state for xmatch and file dfa */ pdb->start[AA_CLASS_FILE] = DFA_START; } /* setup class index */ for (i = AA_CLASS_FILE + 1; i <= AA_CLASS_LAST; i++) { pdb->start[i] = aa_dfa_next(pdb->dfa, pdb->start[0], i); } if (!unpack_trans_table(e, &pdb->trans) && required_trans) { *info = "failed to unpack profile transition table"; goto fail; } /* TODO: move compat mapping here, requires dfa merging first */ /* TODO: move verify here, it has to be done after compat mappings */ out: *policy = pdb; return 0; fail: aa_put_pdb(pdb); e->pos = pos; return error; } static u32 strhash(const void *data, u32 len, u32 seed) { const char * const *key = data; return jhash(*key, strlen(*key), seed); } static int datacmp(struct rhashtable_compare_arg *arg, const void *obj) { const struct aa_data *data = obj; const char * const *key = arg->key; return strcmp(data->key, *key); } /** * unpack_profile - unpack a serialized profile * @e: serialized data extent information (NOT NULL) * @ns_name: pointer of newly allocated copy of %NULL in case of error * * NOTE: unpack profile sets audit struct if there is a failure */ static struct aa_profile *unpack_profile(struct aa_ext *e, char **ns_name) { struct aa_ruleset *rules; struct aa_profile *profile = NULL; const char *tmpname, *tmpns = NULL, *name = NULL; const char *info = "failed to unpack profile"; size_t ns_len; struct rhashtable_params params = { 0 }; char *key = NULL, *disconnected = NULL; struct aa_data *data; int error = -EPROTO; kernel_cap_t tmpcap; u32 tmp; *ns_name = NULL; /* check that we have the right struct being passed */ if (!aa_unpack_nameX(e, AA_STRUCT, "profile")) goto fail; if (!aa_unpack_str(e, &name, NULL)) goto fail; if (*name == '\0') goto fail; tmpname = aa_splitn_fqname(name, strlen(name), &tmpns, &ns_len); if (tmpns) { *ns_name = kstrndup(tmpns, ns_len, GFP_KERNEL); if (!*ns_name) { info = "out of memory"; error = -ENOMEM; goto fail; } name = tmpname; } profile = aa_alloc_profile(name, NULL, GFP_KERNEL); if (!profile) { info = "out of memory"; error = -ENOMEM; goto fail; } rules = list_first_entry(&profile->rules, typeof(*rules), list); /* profile renaming is optional */ (void) aa_unpack_str(e, &profile->rename, "rename"); /* attachment string is optional */ (void) aa_unpack_str(e, &profile->attach.xmatch_str, "attach"); /* xmatch is optional and may be NULL */ error = unpack_pdb(e, &profile->attach.xmatch, false, false, &info); if (error) { info = "bad xmatch"; goto fail; } /* neither xmatch_len not xmatch_perms are optional if xmatch is set */ if (profile->attach.xmatch->dfa) { if (!aa_unpack_u32(e, &tmp, NULL)) { info = "missing xmatch len"; goto fail; } profile->attach.xmatch_len = tmp; profile->attach.xmatch->start[AA_CLASS_XMATCH] = DFA_START; if (!profile->attach.xmatch->perms) { error = aa_compat_map_xmatch(profile->attach.xmatch); if (error) { info = "failed to convert xmatch permission table"; goto fail; } } } /* disconnected attachment string is optional */ (void) aa_unpack_strdup(e, &disconnected, "disconnected"); profile->disconnected = disconnected; /* per profile debug flags (complain, audit) */ if (!aa_unpack_nameX(e, AA_STRUCT, "flags")) { info = "profile missing flags"; goto fail; } info = "failed to unpack profile flags"; if (!aa_unpack_u32(e, &tmp, NULL)) goto fail; if (tmp & PACKED_FLAG_HAT) profile->label.flags |= FLAG_HAT; if (tmp & PACKED_FLAG_DEBUG1) profile->label.flags |= FLAG_DEBUG1; if (tmp & PACKED_FLAG_DEBUG2) profile->label.flags |= FLAG_DEBUG2; if (!aa_unpack_u32(e, &tmp, NULL)) goto fail; if (tmp == PACKED_MODE_COMPLAIN || (e->version & FORCE_COMPLAIN_FLAG)) { profile->mode = APPARMOR_COMPLAIN; } else if (tmp == PACKED_MODE_ENFORCE) { profile->mode = APPARMOR_ENFORCE; } else if (tmp == PACKED_MODE_KILL) { profile->mode = APPARMOR_KILL; } else if (tmp == PACKED_MODE_UNCONFINED) { profile->mode = APPARMOR_UNCONFINED; profile->label.flags |= FLAG_UNCONFINED; } else if (tmp == PACKED_MODE_USER) { profile->mode = APPARMOR_USER; } else { goto fail; } if (!aa_unpack_u32(e, &tmp, NULL)) goto fail; if (tmp) profile->audit = AUDIT_ALL; if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) goto fail; /* path_flags is optional */ if (aa_unpack_u32(e, &profile->path_flags, "path_flags")) profile->path_flags |= profile->label.flags & PATH_MEDIATE_DELETED; else /* set a default value if path_flags field is not present */ profile->path_flags = PATH_MEDIATE_DELETED; info = "failed to unpack profile capabilities"; if (!aa_unpack_cap_low(e, &rules->caps.allow, NULL)) goto fail; if (!aa_unpack_cap_low(e, &rules->caps.audit, NULL)) goto fail; if (!aa_unpack_cap_low(e, &rules->caps.quiet, NULL)) goto fail; if (!aa_unpack_cap_low(e, &tmpcap, NULL)) goto fail; info = "failed to unpack upper profile capabilities"; if (aa_unpack_nameX(e, AA_STRUCT, "caps64")) { /* optional upper half of 64 bit caps */ if (!aa_unpack_cap_high(e, &rules->caps.allow, NULL)) goto fail; if (!aa_unpack_cap_high(e, &rules->caps.audit, NULL)) goto fail; if (!aa_unpack_cap_high(e, &rules->caps.quiet, NULL)) goto fail; if (!aa_unpack_cap_high(e, &tmpcap, NULL)) goto fail; if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) goto fail; } info = "failed to unpack extended profile capabilities"; if (aa_unpack_nameX(e, AA_STRUCT, "capsx")) { /* optional extended caps mediation mask */ if (!aa_unpack_cap_low(e, &rules->caps.extended, NULL)) goto fail; if (!aa_unpack_cap_high(e, &rules->caps.extended, NULL)) goto fail; if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) goto fail; } if (!unpack_xattrs(e, profile)) { info = "failed to unpack profile xattrs"; goto fail; } if (!unpack_rlimits(e, rules)) { info = "failed to unpack profile rlimits"; goto fail; } if (!unpack_secmark(e, rules)) { info = "failed to unpack profile secmark rules"; goto fail; } if (aa_unpack_nameX(e, AA_STRUCT, "policydb")) { /* generic policy dfa - optional and may be NULL */ info = "failed to unpack policydb"; error = unpack_pdb(e, &rules->policy, true, false, &info); if (error) goto fail; /* Fixup: drop when we get rid of start array */ if (aa_dfa_next(rules->policy->dfa, rules->policy->start[0], AA_CLASS_FILE)) rules->policy->start[AA_CLASS_FILE] = aa_dfa_next(rules->policy->dfa, rules->policy->start[0], AA_CLASS_FILE); if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) goto fail; if (!rules->policy->perms) { error = aa_compat_map_policy(rules->policy, e->version); if (error) { info = "failed to remap policydb permission table"; goto fail; } } } else { rules->policy = aa_get_pdb(nullpdb); } /* get file rules */ error = unpack_pdb(e, &rules->file, false, true, &info); if (error) { goto fail; } else if (rules->file->dfa) { if (!rules->file->perms) { error = aa_compat_map_file(rules->file); if (error) { info = "failed to remap file permission table"; goto fail; } } } else if (rules->policy->dfa && rules->policy->start[AA_CLASS_FILE]) { rules->file = aa_get_pdb(rules->policy); } else { rules->file = aa_get_pdb(nullpdb); } error = -EPROTO; if (aa_unpack_nameX(e, AA_STRUCT, "data")) { info = "out of memory"; profile->data = kzalloc(sizeof(*profile->data), GFP_KERNEL); if (!profile->data) { error = -ENOMEM; goto fail; } params.nelem_hint = 3; params.key_len = sizeof(void *); params.key_offset = offsetof(struct aa_data, key); params.head_offset = offsetof(struct aa_data, head); params.hashfn = strhash; params.obj_cmpfn = datacmp; if (rhashtable_init(profile->data, ¶ms)) { info = "failed to init key, value hash table"; goto fail; } while (aa_unpack_strdup(e, &key, NULL)) { data = kzalloc(sizeof(*data), GFP_KERNEL); if (!data) { kfree_sensitive(key); error = -ENOMEM; goto fail; } data->key = key; data->size = aa_unpack_blob(e, &data->data, NULL); data->data = kvmemdup(data->data, data->size, GFP_KERNEL); if (data->size && !data->data) { kfree_sensitive(data->key); kfree_sensitive(data); error = -ENOMEM; goto fail; } if (rhashtable_insert_fast(profile->data, &data->head, profile->data->p)) { kfree_sensitive(data->key); kfree_sensitive(data); info = "failed to insert data to table"; goto fail; } } if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) { info = "failed to unpack end of key, value data table"; goto fail; } } if (!aa_unpack_nameX(e, AA_STRUCTEND, NULL)) { info = "failed to unpack end of profile"; goto fail; } return profile; fail: if (error == 0) /* default error covers most cases */ error = -EPROTO; if (*ns_name) { kfree(*ns_name); *ns_name = NULL; } if (profile) name = NULL; else if (!name) name = "unknown"; audit_iface(profile, NULL, name, info, e, error); aa_free_profile(profile); return ERR_PTR(error); } /** * verify_header - unpack serialized stream header * @e: serialized data read head (NOT NULL) * @required: whether the header is required or optional * @ns: Returns - namespace if one is specified else NULL (NOT NULL) * * Returns: error or 0 if header is good */ static int verify_header(struct aa_ext *e, int required, const char **ns) { int error = -EPROTONOSUPPORT; const char *name = NULL; *ns = NULL; /* get the interface version */ if (!aa_unpack_u32(e, &e->version, "version")) { if (required) { audit_iface(NULL, NULL, NULL, "invalid profile format", e, error); return error; } } /* Check that the interface version is currently supported. * if not specified use previous version * Mask off everything that is not kernel abi version */ if (VERSION_LT(e->version, v5) || VERSION_GT(e->version, v9)) { audit_iface(NULL, NULL, NULL, "unsupported interface version", e, error); return error; } /* read the namespace if present */ if (aa_unpack_str(e, &name, "namespace")) { if (*name == '\0') { audit_iface(NULL, NULL, NULL, "invalid namespace name", e, error); return error; } if (*ns && strcmp(*ns, name)) { audit_iface(NULL, NULL, NULL, "invalid ns change", e, error); } else if (!*ns) { *ns = kstrdup(name, GFP_KERNEL); if (!*ns) return -ENOMEM; } } return 0; } /** * verify_dfa_accept_index - verify accept indexes are in range of perms table * @dfa: the dfa to check accept indexes are in range * @table_size: the permission table size the indexes should be within */ static bool verify_dfa_accept_index(struct aa_dfa *dfa, int table_size) { int i; for (i = 0; i < dfa->tables[YYTD_ID_ACCEPT]->td_lolen; i++) { if (ACCEPT_TABLE(dfa)[i] >= table_size) return false; } return true; } static bool verify_perm(struct aa_perms *perm) { /* TODO: allow option to just force the perms into a valid state */ if (perm->allow & perm->deny) return false; if (perm->subtree & ~perm->allow) return false; if (perm->cond & (perm->allow | perm->deny)) return false; if (perm->kill & perm->allow) return false; if (perm->complain & (perm->allow | perm->deny)) return false; if (perm->prompt & (perm->allow | perm->deny)) return false; if (perm->complain & perm->prompt) return false; if (perm->hide & perm->allow) return false; return true; } static bool verify_perms(struct aa_policydb *pdb) { int i; for (i = 0; i < pdb->size; i++) { if (!verify_perm(&pdb->perms[i])) return false; /* verify indexes into str table */ if ((pdb->perms[i].xindex & AA_X_TYPE_MASK) == AA_X_TABLE && (pdb->perms[i].xindex & AA_X_INDEX_MASK) >= pdb->trans.size) return false; if (pdb->perms[i].tag && pdb->perms[i].tag >= pdb->trans.size) return false; if (pdb->perms[i].label && pdb->perms[i].label >= pdb->trans.size) return false; } return true; } /** * verify_profile - Do post unpack analysis to verify profile consistency * @profile: profile to verify (NOT NULL) * * Returns: 0 if passes verification else error * * This verification is post any unpack mapping or changes */ static int verify_profile(struct aa_profile *profile) { struct aa_ruleset *rules = list_first_entry(&profile->rules, typeof(*rules), list); if (!rules) return 0; if (rules->file->dfa && !verify_dfa_accept_index(rules->file->dfa, rules->file->size)) { audit_iface(profile, NULL, NULL, "Unpack: file Invalid named transition", NULL, -EPROTO); return -EPROTO; } if (rules->policy->dfa && !verify_dfa_accept_index(rules->policy->dfa, rules->policy->size)) { audit_iface(profile, NULL, NULL, "Unpack: policy Invalid named transition", NULL, -EPROTO); return -EPROTO; } if (!verify_perms(rules->file)) { audit_iface(profile, NULL, NULL, "Unpack: Invalid perm index", NULL, -EPROTO); return -EPROTO; } if (!verify_perms(rules->policy)) { audit_iface(profile, NULL, NULL, "Unpack: Invalid perm index", NULL, -EPROTO); return -EPROTO; } if (!verify_perms(profile->attach.xmatch)) { audit_iface(profile, NULL, NULL, "Unpack: Invalid perm index", NULL, -EPROTO); return -EPROTO; } return 0; } void aa_load_ent_free(struct aa_load_ent *ent) { if (ent) { aa_put_profile(ent->rename); aa_put_profile(ent->old); aa_put_profile(ent->new); kfree(ent->ns_name); kfree_sensitive(ent); } } struct aa_load_ent *aa_load_ent_alloc(void) { struct aa_load_ent *ent = kzalloc(sizeof(*ent), GFP_KERNEL); if (ent) INIT_LIST_HEAD(&ent->list); return ent; } static int compress_zstd(const char *src, size_t slen, char **dst, size_t *dlen) { #ifdef CONFIG_SECURITY_APPARMOR_EXPORT_BINARY const zstd_parameters params = zstd_get_params(aa_g_rawdata_compression_level, slen); const size_t wksp_len = zstd_cctx_workspace_bound(¶ms.cParams); void *wksp = NULL; zstd_cctx *ctx = NULL; size_t out_len = zstd_compress_bound(slen); void *out = NULL; int ret = 0; out = kvzalloc(out_len, GFP_KERNEL); if (!out) { ret = -ENOMEM; goto cleanup; } wksp = kvzalloc(wksp_len, GFP_KERNEL); if (!wksp) { ret = -ENOMEM; goto cleanup; } ctx = zstd_init_cctx(wksp, wksp_len); if (!ctx) { ret = -EINVAL; goto cleanup; } out_len = zstd_compress_cctx(ctx, out, out_len, src, slen, ¶ms); if (zstd_is_error(out_len) || out_len >= slen) { ret = -EINVAL; goto cleanup; } if (is_vmalloc_addr(out)) { *dst = kvzalloc(out_len, GFP_KERNEL); if (*dst) { memcpy(*dst, out, out_len); kvfree(out); out = NULL; } } else { /* * If the staging buffer was kmalloc'd, then using krealloc is * probably going to be faster. The destination buffer will * always be smaller, so it's just shrunk, avoiding a memcpy */ *dst = krealloc(out, out_len, GFP_KERNEL); } if (!*dst) { ret = -ENOMEM; goto cleanup; } *dlen = out_len; cleanup: if (ret) { kvfree(out); *dst = NULL; } kvfree(wksp); return ret; #else *dlen = slen; return 0; #endif } static int compress_loaddata(struct aa_loaddata *data) { AA_BUG(data->compressed_size > 0); /* * Shortcut the no compression case, else we increase the amount of * storage required by a small amount */ if (aa_g_rawdata_compression_level != 0) { void *udata = data->data; int error = compress_zstd(udata, data->size, &data->data, &data->compressed_size); if (error) { data->compressed_size = data->size; return error; } if (udata != data->data) kvfree(udata); } else data->compressed_size = data->size; return 0; } /** * aa_unpack - unpack packed binary profile(s) data loaded from user space * @udata: user data copied to kmem (NOT NULL) * @lh: list to place unpacked profiles in a aa_repl_ws * @ns: Returns namespace profile is in if specified else NULL (NOT NULL) * * Unpack user data and return refcounted allocated profile(s) stored in * @lh in order of discovery, with the list chain stored in base.list * or error * * Returns: profile(s) on @lh else error pointer if fails to unpack */ int aa_unpack(struct aa_loaddata *udata, struct list_head *lh, const char **ns) { struct aa_load_ent *tmp, *ent; struct aa_profile *profile = NULL; char *ns_name = NULL; int error; struct aa_ext e = { .start = udata->data, .end = udata->data + udata->size, .pos = udata->data, }; *ns = NULL; while (e.pos < e.end) { void *start; error = verify_header(&e, e.pos == e.start, ns); if (error) goto fail; start = e.pos; profile = unpack_profile(&e, &ns_name); if (IS_ERR(profile)) { error = PTR_ERR(profile); goto fail; } error = verify_profile(profile); if (error) goto fail_profile; if (aa_g_hash_policy) error = aa_calc_profile_hash(profile, e.version, start, e.pos - start); if (error) goto fail_profile; ent = aa_load_ent_alloc(); if (!ent) { error = -ENOMEM; goto fail_profile; } ent->new = profile; ent->ns_name = ns_name; ns_name = NULL; list_add_tail(&ent->list, lh); } udata->abi = e.version & K_ABI_MASK; if (aa_g_hash_policy) { udata->hash = aa_calc_hash(udata->data, udata->size); if (IS_ERR(udata->hash)) { error = PTR_ERR(udata->hash); udata->hash = NULL; goto fail; } } if (aa_g_export_binary) { error = compress_loaddata(udata); if (error) goto fail; } return 0; fail_profile: kfree(ns_name); aa_put_profile(profile); fail: list_for_each_entry_safe(ent, tmp, lh, list) { list_del_init(&ent->list); aa_load_ent_free(ent); } return error; }