// 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 <asm/unaligned.h> #include <linux/ctype.h> #include <linux/errno.h> #include <linux/zlib.h> #include "include/apparmor.h" #include "include/audit.h" #include "include/cred.h" #include "include/crypto.h" #include "include/match.h" #include "include/path.h" #include "include/policy.h" #include "include/policy_unpack.h" #define K_ABI_MASK 0x3ff #define FORCE_COMPLAIN_FLAG 0x800 #define VERSION_LT(X, Y) (((X) & K_ABI_MASK) < ((Y) & K_ABI_MASK)) #define VERSION_GT(X, Y) (((X) & K_ABI_MASK) > ((Y) & K_ABI_MASK)) #define v5 5 /* base version */ #define v6 6 /* per entry policydb mediation check */ #define v7 7 #define v8 8 /* full network masking */ /* * The AppArmor interface treats data as a type byte followed by the * actual data. The interface has the notion of a a named entry * which has a name (AA_NAME typecode followed by name string) followed by * the entries typecode and data. Named types allow for optional * elements and extensions to be added and tested for without breaking * backwards compatibility. */ enum aa_code { AA_U8, AA_U16, AA_U32, AA_U64, AA_NAME, /* same as string except it is items name */ AA_STRING, AA_BLOB, AA_STRUCT, AA_STRUCTEND, AA_LIST, AA_LISTEND, AA_ARRAY, AA_ARRAYEND, }; /* * aa_ext is the read of the buffer containing the serialized profile. The * data is copied into a kernel buffer in apparmorfs and then handed off to * the unpack routines. */ struct aa_ext { void *start; void *end; void *pos; /* pointer to current position in the buffer */ u32 version; }; /* audit callback for unpack fields */ static void audit_cb(struct audit_buffer *ab, void *va) { struct common_audit_data *sa = va; if (aad(sa)->iface.ns) { audit_log_format(ab, " ns="); audit_log_untrustedstring(ab, aad(sa)->iface.ns); } if (aad(sa)->name) { audit_log_format(ab, " name="); audit_log_untrustedstring(ab, aad(sa)->name); } if (aad(sa)->iface.pos) audit_log_format(ab, " offset=%ld", aad(sa)->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(sa, LSM_AUDIT_DATA_NONE, NULL); if (e) aad(&sa)->iface.pos = e->pos - e->start; aad(&sa)->iface.ns = ns_name; if (new) aad(&sa)->name = new->base.hname; else aad(&sa)->name = name; aad(&sa)->info = info; aad(&sa)->error = error; return aa_audit(AUDIT_APPARMOR_STATUS, profile, &sa, audit_cb); } void __aa_loaddata_update(struct aa_loaddata *data, long revision) { AA_BUG(!data); AA_BUG(!data->ns); AA_BUG(!data->dents[AAFS_LOADDATA_REVISION]); AA_BUG(!mutex_is_locked(&data->ns->lock)); AA_BUG(data->revision > revision); data->revision = revision; d_inode(data->dents[AAFS_LOADDATA_DIR])->i_mtime = current_time(d_inode(data->dents[AAFS_LOADDATA_DIR])); d_inode(data->dents[AAFS_LOADDATA_REVISION])->i_mtime = current_time(d_inode(data->dents[AAFS_LOADDATA_REVISION])); } 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 */ static bool inbounds(struct aa_ext *e, size_t size) { return (size <= e->end - e->pos); } static void *kvmemdup(const void *src, size_t len) { void *p = kvmalloc(len, GFP_KERNEL); if (p) memcpy(p, src, len); return p; } /** * aa_u16_chunck - 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. */ static size_t unpack_u16_chunk(struct aa_ext *e, char **chunk) { size_t size = 0; void *pos = e->pos; if (!inbounds(e, sizeof(u16))) goto fail; size = le16_to_cpu(get_unaligned((__le16 *) e->pos)); e->pos += sizeof(__le16); if (!inbounds(e, size)) goto fail; *chunk = e->pos; e->pos += size; return size; fail: e->pos = pos; return 0; } /* unpack control byte */ static bool unpack_X(struct aa_ext *e, enum aa_code code) { if (!inbounds(e, 1)) return false; if (*(u8 *) e->pos != code) return false; e->pos++; return true; } /** * 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 */ static bool 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 (unpack_X(e, AA_NAME)) { char *tag = NULL; size_t size = 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 (unpack_X(e, code)) return true; fail: e->pos = pos; return false; } static bool unpack_u8(struct aa_ext *e, u8 *data, const char *name) { void *pos = e->pos; if (unpack_nameX(e, AA_U8, name)) { if (!inbounds(e, sizeof(u8))) goto fail; if (data) *data = get_unaligned((u8 *)e->pos); e->pos += sizeof(u8); return true; } fail: e->pos = pos; return false; } static bool unpack_u32(struct aa_ext *e, u32 *data, const char *name) { void *pos = e->pos; if (unpack_nameX(e, AA_U32, name)) { if (!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; } static bool unpack_u64(struct aa_ext *e, u64 *data, const char *name) { void *pos = e->pos; if (unpack_nameX(e, AA_U64, name)) { if (!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; } static size_t unpack_array(struct aa_ext *e, const char *name) { void *pos = e->pos; if (unpack_nameX(e, AA_ARRAY, name)) { int size; if (!inbounds(e, sizeof(u16))) goto fail; size = (int)le16_to_cpu(get_unaligned((__le16 *) e->pos)); e->pos += sizeof(u16); return size; } fail: e->pos = pos; return 0; } static size_t unpack_blob(struct aa_ext *e, char **blob, const char *name) { void *pos = e->pos; if (unpack_nameX(e, AA_BLOB, name)) { u32 size; if (!inbounds(e, sizeof(u32))) goto fail; size = le32_to_cpu(get_unaligned((__le32 *) e->pos)); e->pos += sizeof(u32); if (inbounds(e, (size_t) size)) { *blob = e->pos; e->pos += size; return size; } } fail: e->pos = pos; return 0; } static int 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 (unpack_nameX(e, AA_STRING, name)) { size = 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; } static int unpack_strdup(struct aa_ext *e, char **string, const char *name) { const char *tmp; void *pos = e->pos; int res = 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; } /** * unpack_dfa - unpack a file rule dfa * @e: serialized data extent information (NOT NULL) * * returns dfa or ERR_PTR or NULL if no dfa */ static struct aa_dfa *unpack_dfa(struct aa_ext *e) { char *blob = NULL; size_t size; struct aa_dfa *dfa = NULL; size = 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; int flags = TO_ACCEPT1_FLAG(YYTD_DATA32) | TO_ACCEPT2_FLAG(YYTD_DATA32) | 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) * @profile: profile to add the accept table to (NOT NULL) * * Returns: true if table successfully unpacked */ static bool unpack_trans_table(struct aa_ext *e, struct aa_profile *profile) { void *saved_pos = e->pos; /* exec table is optional */ if (unpack_nameX(e, AA_STRUCT, "xtable")) { int i, size; size = unpack_array(e, NULL); /* currently 4 exec bits and entries 0-3 are reserved iupcx */ if (size > 16 - 4) goto fail; profile->file.trans.table = kcalloc(size, sizeof(char *), GFP_KERNEL); if (!profile->file.trans.table) goto fail; profile->file.trans.size = size; for (i = 0; i < size; i++) { char *str; int c, j, pos, size2 = unpack_strdup(e, &str, NULL); /* unpack_strdup verifies that the last character is * null termination byte. */ if (!size2) goto fail; profile->file.trans.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 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 (!unpack_nameX(e, AA_ARRAYEND, NULL)) goto fail; if (!unpack_nameX(e, AA_STRUCTEND, NULL)) goto fail; } return true; fail: aa_free_domain_entries(&profile->file.trans); e->pos = saved_pos; return false; } static bool unpack_xattrs(struct aa_ext *e, struct aa_profile *profile) { void *pos = e->pos; if (unpack_nameX(e, AA_STRUCT, "xattrs")) { int i, size; size = unpack_array(e, NULL); profile->xattr_count = size; profile->xattrs = kcalloc(size, sizeof(char *), GFP_KERNEL); if (!profile->xattrs) goto fail; for (i = 0; i < size; i++) { if (!unpack_strdup(e, &profile->xattrs[i], NULL)) goto fail; } if (!unpack_nameX(e, AA_ARRAYEND, NULL)) goto fail; if (!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_profile *profile) { void *pos = e->pos; int i, size; if (unpack_nameX(e, AA_STRUCT, "secmark")) { size = unpack_array(e, NULL); profile->secmark = kcalloc(size, sizeof(struct aa_secmark), GFP_KERNEL); if (!profile->secmark) goto fail; profile->secmark_count = size; for (i = 0; i < size; i++) { if (!unpack_u8(e, &profile->secmark[i].audit, NULL)) goto fail; if (!unpack_u8(e, &profile->secmark[i].deny, NULL)) goto fail; if (!unpack_strdup(e, &profile->secmark[i].label, NULL)) goto fail; } if (!unpack_nameX(e, AA_ARRAYEND, NULL)) goto fail; if (!unpack_nameX(e, AA_STRUCTEND, NULL)) goto fail; } return true; fail: if (profile->secmark) { for (i = 0; i < size; i++) kfree(profile->secmark[i].label); kfree(profile->secmark); profile->secmark_count = 0; profile->secmark = NULL; } e->pos = pos; return false; } static bool unpack_rlimits(struct aa_ext *e, struct aa_profile *profile) { void *pos = e->pos; /* rlimits are optional */ if (unpack_nameX(e, AA_STRUCT, "rlimits")) { int i, size; u32 tmp = 0; if (!unpack_u32(e, &tmp, NULL)) goto fail; profile->rlimits.mask = tmp; size = unpack_array(e, NULL); if (size > RLIM_NLIMITS) goto fail; for (i = 0; i < size; i++) { u64 tmp2 = 0; int a = aa_map_resource(i); if (!unpack_u64(e, &tmp2, NULL)) goto fail; profile->rlimits.limits[a].rlim_max = tmp2; } if (!unpack_nameX(e, AA_ARRAYEND, NULL)) goto fail; if (!unpack_nameX(e, AA_STRUCTEND, NULL)) goto fail; } return true; fail: e->pos = pos; return false; } 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) * * 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_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; struct aa_data *data; int i, error = -EPROTO; kernel_cap_t tmpcap; u32 tmp; *ns_name = NULL; /* check that we have the right struct being passed */ if (!unpack_nameX(e, AA_STRUCT, "profile")) goto fail; if (!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"; goto fail; } name = tmpname; } profile = aa_alloc_profile(name, NULL, GFP_KERNEL); if (!profile) return ERR_PTR(-ENOMEM); /* profile renaming is optional */ (void) unpack_str(e, &profile->rename, "rename"); /* attachment string is optional */ (void) unpack_str(e, &profile->attach, "attach"); /* xmatch is optional and may be NULL */ profile->xmatch = unpack_dfa(e); if (IS_ERR(profile->xmatch)) { error = PTR_ERR(profile->xmatch); profile->xmatch = NULL; info = "bad xmatch"; goto fail; } /* xmatch_len is not optional if xmatch is set */ if (profile->xmatch) { if (!unpack_u32(e, &tmp, NULL)) { info = "missing xmatch len"; goto fail; } profile->xmatch_len = tmp; } /* disconnected attachment string is optional */ (void) unpack_str(e, &profile->disconnected, "disconnected"); /* per profile debug flags (complain, audit) */ if (!unpack_nameX(e, AA_STRUCT, "flags")) { info = "profile missing flags"; goto fail; } info = "failed to unpack profile flags"; if (!unpack_u32(e, &tmp, NULL)) goto fail; if (tmp & PACKED_FLAG_HAT) profile->label.flags |= FLAG_HAT; if (!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; else goto fail; if (!unpack_u32(e, &tmp, NULL)) goto fail; if (tmp) profile->audit = AUDIT_ALL; if (!unpack_nameX(e, AA_STRUCTEND, NULL)) goto fail; /* path_flags is optional */ if (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 (!unpack_u32(e, &(profile->caps.allow.cap[0]), NULL)) goto fail; if (!unpack_u32(e, &(profile->caps.audit.cap[0]), NULL)) goto fail; if (!unpack_u32(e, &(profile->caps.quiet.cap[0]), NULL)) goto fail; if (!unpack_u32(e, &tmpcap.cap[0], NULL)) goto fail; info = "failed to unpack upper profile capabilities"; if (unpack_nameX(e, AA_STRUCT, "caps64")) { /* optional upper half of 64 bit caps */ if (!unpack_u32(e, &(profile->caps.allow.cap[1]), NULL)) goto fail; if (!unpack_u32(e, &(profile->caps.audit.cap[1]), NULL)) goto fail; if (!unpack_u32(e, &(profile->caps.quiet.cap[1]), NULL)) goto fail; if (!unpack_u32(e, &(tmpcap.cap[1]), NULL)) goto fail; if (!unpack_nameX(e, AA_STRUCTEND, NULL)) goto fail; } info = "failed to unpack extended profile capabilities"; if (unpack_nameX(e, AA_STRUCT, "capsx")) { /* optional extended caps mediation mask */ if (!unpack_u32(e, &(profile->caps.extended.cap[0]), NULL)) goto fail; if (!unpack_u32(e, &(profile->caps.extended.cap[1]), NULL)) goto fail; if (!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, profile)) { info = "failed to unpack profile rlimits"; goto fail; } if (!unpack_secmark(e, profile)) { info = "failed to unpack profile secmark rules"; goto fail; } if (unpack_nameX(e, AA_STRUCT, "policydb")) { /* generic policy dfa - optional and may be NULL */ info = "failed to unpack policydb"; profile->policy.dfa = unpack_dfa(e); if (IS_ERR(profile->policy.dfa)) { error = PTR_ERR(profile->policy.dfa); profile->policy.dfa = NULL; goto fail; } else if (!profile->policy.dfa) { error = -EPROTO; goto fail; } if (!unpack_u32(e, &profile->policy.start[0], "start")) /* default start state */ profile->policy.start[0] = DFA_START; /* setup class index */ for (i = AA_CLASS_FILE; i <= AA_CLASS_LAST; i++) { profile->policy.start[i] = aa_dfa_next(profile->policy.dfa, profile->policy.start[0], i); } if (!unpack_nameX(e, AA_STRUCTEND, NULL)) goto fail; } else profile->policy.dfa = aa_get_dfa(nulldfa); /* get file rules */ profile->file.dfa = unpack_dfa(e); if (IS_ERR(profile->file.dfa)) { error = PTR_ERR(profile->file.dfa); profile->file.dfa = NULL; info = "failed to unpack profile file rules"; goto fail; } else if (profile->file.dfa) { if (!unpack_u32(e, &profile->file.start, "dfa_start")) /* default start state */ profile->file.start = DFA_START; } else if (profile->policy.dfa && profile->policy.start[AA_CLASS_FILE]) { profile->file.dfa = aa_get_dfa(profile->policy.dfa); profile->file.start = profile->policy.start[AA_CLASS_FILE]; } else profile->file.dfa = aa_get_dfa(nulldfa); if (!unpack_trans_table(e, profile)) { info = "failed to unpack profile transition table"; goto fail; } if (unpack_nameX(e, AA_STRUCT, "data")) { info = "out of memory"; profile->data = kzalloc(sizeof(*profile->data), GFP_KERNEL); if (!profile->data) 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 (unpack_strdup(e, &key, NULL)) { data = kzalloc(sizeof(*data), GFP_KERNEL); if (!data) { kfree_sensitive(key); goto fail; } data->key = key; data->size = unpack_blob(e, &data->data, NULL); data->data = kvmemdup(data->data, data->size); if (data->size && !data->data) { kfree_sensitive(data->key); kfree_sensitive(data); goto fail; } rhashtable_insert_fast(profile->data, &data->head, profile->data->p); } if (!unpack_nameX(e, AA_STRUCTEND, NULL)) { info = "failed to unpack end of key, value data table"; goto fail; } } if (!unpack_nameX(e, AA_STRUCTEND, NULL)) { info = "failed to unpack end of profile"; goto fail; } return profile; fail: 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_head - 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 (!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, v7)) { audit_iface(NULL, NULL, NULL, "unsupported interface version", e, error); return error; } /* read the namespace if present */ if (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; } static bool verify_xindex(int xindex, int table_size) { int index, xtype; xtype = xindex & AA_X_TYPE_MASK; index = xindex & AA_X_INDEX_MASK; if (xtype == AA_X_TABLE && index >= table_size) return false; return true; } /* verify dfa xindexes are in range of transition tables */ static bool verify_dfa_xindex(struct aa_dfa *dfa, int table_size) { int i; for (i = 0; i < dfa->tables[YYTD_ID_ACCEPT]->td_lolen; i++) { if (!verify_xindex(dfa_user_xindex(dfa, i), table_size)) return false; if (!verify_xindex(dfa_other_xindex(dfa, i), table_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 */ static int verify_profile(struct aa_profile *profile) { if (profile->file.dfa && !verify_dfa_xindex(profile->file.dfa, profile->file.trans.size)) { audit_iface(profile, NULL, NULL, "Invalid named transition", 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 deflate_compress(const char *src, size_t slen, char **dst, size_t *dlen) { int error; struct z_stream_s strm; void *stgbuf, *dstbuf; size_t stglen = deflateBound(slen); memset(&strm, 0, sizeof(strm)); if (stglen < slen) return -EFBIG; strm.workspace = kvzalloc(zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL), GFP_KERNEL); if (!strm.workspace) return -ENOMEM; error = zlib_deflateInit(&strm, aa_g_rawdata_compression_level); if (error != Z_OK) { error = -ENOMEM; goto fail_deflate_init; } stgbuf = kvzalloc(stglen, GFP_KERNEL); if (!stgbuf) { error = -ENOMEM; goto fail_stg_alloc; } strm.next_in = src; strm.avail_in = slen; strm.next_out = stgbuf; strm.avail_out = stglen; error = zlib_deflate(&strm, Z_FINISH); if (error != Z_STREAM_END) { error = -EINVAL; goto fail_deflate; } error = 0; if (is_vmalloc_addr(stgbuf)) { dstbuf = kvzalloc(strm.total_out, GFP_KERNEL); if (dstbuf) { memcpy(dstbuf, stgbuf, strm.total_out); kvfree(stgbuf); } } 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 */ dstbuf = krealloc(stgbuf, strm.total_out, GFP_KERNEL); if (!dstbuf) { error = -ENOMEM; goto fail_deflate; } *dst = dstbuf; *dlen = strm.total_out; fail_stg_alloc: zlib_deflateEnd(&strm); fail_deflate_init: kvfree(strm.workspace); return error; fail_deflate: kvfree(stgbuf); goto fail_stg_alloc; } 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 = deflate_compress(udata, data->size, &data->data, &data->compressed_size); if (error) return error; 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; int error; struct aa_ext e = { .start = udata->data, .end = udata->data + udata->size, .pos = udata->data, }; *ns = NULL; while (e.pos < e.end) { char *ns_name = NULL; 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; 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; } } error = compress_loaddata(udata); if (error) goto fail; return 0; fail_profile: 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; } #ifdef CONFIG_SECURITY_APPARMOR_KUNIT_TEST #include "policy_unpack_test.c" #endif /* CONFIG_SECURITY_APPARMOR_KUNIT_TEST */