diff options
Diffstat (limited to 'ANDROID_3.4.5/security/apparmor/policy_unpack.c')
| -rw-r--r-- | ANDROID_3.4.5/security/apparmor/policy_unpack.c | 730 |
1 files changed, 0 insertions, 730 deletions
diff --git a/ANDROID_3.4.5/security/apparmor/policy_unpack.c b/ANDROID_3.4.5/security/apparmor/policy_unpack.c deleted file mode 100644 index deab7c7e..00000000 --- a/ANDROID_3.4.5/security/apparmor/policy_unpack.c +++ /dev/null @@ -1,730 +0,0 @@ -/* - * 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. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License as - * published by the Free Software Foundation, version 2 of the - * License. - * - * AppArmor uses a serialized binary format for loading policy. To find - * policy format documentation look in Documentation/security/apparmor.txt - * All policy is validated before it is used. - */ - -#include <asm/unaligned.h> -#include <linux/ctype.h> -#include <linux/errno.h> - -#include "include/apparmor.h" -#include "include/audit.h" -#include "include/context.h" -#include "include/match.h" -#include "include/policy.h" -#include "include/policy_unpack.h" -#include "include/sid.h" - -/* - * 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 (sa->aad->iface.target) { - struct aa_profile *name = sa->aad->iface.target; - audit_log_format(ab, " name="); - audit_log_untrustedstring(ab, name->base.hname); - } - if (sa->aad->iface.pos) - audit_log_format(ab, " offset=%ld", sa->aad->iface.pos); -} - -/** - * audit_iface - do audit message for policy unpacking/load/replace/remove - * @new: profile if it has been allocated (MAYBE 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 *name, - const char *info, struct aa_ext *e, int error) -{ - struct aa_profile *profile = __aa_current_profile(); - struct common_audit_data sa; - struct apparmor_audit_data aad = {0,}; - COMMON_AUDIT_DATA_INIT(&sa, NONE); - sa.aad = &aad; - if (e) - aad.iface.pos = e->pos - e->start; - aad.iface.target = new; - aad.name = name; - aad.info = info; - aad.error = error; - - return aa_audit(AUDIT_APPARMOR_STATUS, profile, GFP_KERNEL, &sa, - audit_cb); -} - -/* 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); -} - -/** - * 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; - - if (!inbounds(e, sizeof(u16))) - return 0; - size = le16_to_cpu(get_unaligned((u16 *) e->pos)); - e->pos += sizeof(u16); - if (!inbounds(e, size)) - return 0; - *chunk = e->pos; - e->pos += size; - return size; -} - -/* unpack control byte */ -static bool unpack_X(struct aa_ext *e, enum aa_code code) -{ - if (!inbounds(e, 1)) - return 0; - if (*(u8 *) e->pos != code) - return 0; - e->pos++; - return 1; -} - -/** - * 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 1 on success (both type code and name tests match) and the read - * head is advanced past the headers - * - * Returns: 0 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 || 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 1; - -fail: - e->pos = pos; - return 0; -} - -static bool unpack_u32(struct aa_ext *e, u32 *data, const char *name) -{ - if (unpack_nameX(e, AA_U32, name)) { - if (!inbounds(e, sizeof(u32))) - return 0; - if (data) - *data = le32_to_cpu(get_unaligned((u32 *) e->pos)); - e->pos += sizeof(u32); - return 1; - } - return 0; -} - -static bool unpack_u64(struct aa_ext *e, u64 *data, const char *name) -{ - if (unpack_nameX(e, AA_U64, name)) { - if (!inbounds(e, sizeof(u64))) - return 0; - if (data) - *data = le64_to_cpu(get_unaligned((u64 *) e->pos)); - e->pos += sizeof(u64); - return 1; - } - return 0; -} - -static size_t unpack_array(struct aa_ext *e, const char *name) -{ - if (unpack_nameX(e, AA_ARRAY, name)) { - int size; - if (!inbounds(e, sizeof(u16))) - return 0; - size = (int)le16_to_cpu(get_unaligned((u16 *) e->pos)); - e->pos += sizeof(u16); - return size; - } - return 0; -} - -static size_t unpack_blob(struct aa_ext *e, char **blob, const char *name) -{ - if (unpack_nameX(e, AA_BLOB, name)) { - u32 size; - if (!inbounds(e, sizeof(u32))) - return 0; - size = le32_to_cpu(get_unaligned((u32 *) e->pos)); - e->pos += sizeof(u32); - if (inbounds(e, (size_t) size)) { - *blob = e->pos; - e->pos += size; - return size; - } - } - 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; -} - -/** - * verify_accept - verify the accept tables of a dfa - * @dfa: dfa to verify accept tables of (NOT NULL) - * @flags: flags governing dfa - * - * Returns: 1 if valid accept tables else 0 if error - */ -static bool verify_accept(struct aa_dfa *dfa, int flags) -{ - int i; - - /* verify accept permissions */ - for (i = 0; i < dfa->tables[YYTD_ID_ACCEPT]->td_lolen; i++) { - int mode = ACCEPT_TABLE(dfa)[i]; - - if (mode & ~DFA_VALID_PERM_MASK) - return 0; - - if (ACCEPT_TABLE2(dfa)[i] & ~DFA_VALID_PERM2_MASK) - return 0; - } - return 1; -} - -/** - * 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. - */ - size_t sz = blob - (char *)e->start; - size_t pad = ALIGN(sz, 8) - sz; - int flags = TO_ACCEPT1_FLAG(YYTD_DATA32) | - TO_ACCEPT2_FLAG(YYTD_DATA32); - - - 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; - - if (!verify_accept(dfa, flags)) - goto fail; - } - - return dfa; - -fail: - aa_put_dfa(dfa); - return ERR_PTR(-EPROTO); -} - -/** - * 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: 1 if table successfully unpacked - */ -static bool unpack_trans_table(struct aa_ext *e, struct aa_profile *profile) -{ - void *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 = kzalloc(sizeof(char *) * size, - 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, 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 - 2; j++) { - if (!str[j]) - c++; - } - if (*str == ':') { - /* beginning with : requires an embedded \0, - * verify that exactly 1 internal \0 exists - * trailing \0 already verified by unpack_strdup - */ - if (c != 1) - goto fail; - /* first character after : must be valid */ - if (!str[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 1; - -fail: - aa_free_domain_entries(&profile->file.trans); - e->pos = pos; - return 0; -} - -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 1; - -fail: - e->pos = pos; - return 0; -} - -/** - * 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) -{ - struct aa_profile *profile = NULL; - const char *name = NULL; - int i, error = -EPROTO; - kernel_cap_t tmpcap; - u32 tmp; - - /* 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; - - profile = aa_alloc_profile(name); - if (!profile) - return ERR_PTR(-ENOMEM); - - /* profile renaming is optional */ - (void) unpack_str(e, &profile->rename, "rename"); - - /* 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; - goto fail; - } - /* xmatch_len is not optional if xmatch is set */ - if (profile->xmatch) { - if (!unpack_u32(e, &tmp, NULL)) - goto fail; - profile->xmatch_len = tmp; - } - - /* per profile debug flags (complain, audit) */ - if (!unpack_nameX(e, AA_STRUCT, "flags")) - goto fail; - if (!unpack_u32(e, &tmp, NULL)) - goto fail; - if (tmp) - profile->flags |= PFLAG_HAT; - if (!unpack_u32(e, &tmp, NULL)) - goto fail; - if (tmp) - profile->mode = APPARMOR_COMPLAIN; - 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->flags & PFLAG_MEDIATE_DELETED; - else - /* set a default value if path_flags field is not present */ - profile->path_flags = PFLAG_MEDIATE_DELETED; - - 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; - - 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; - } - - 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_rlimits(e, profile)) - goto fail; - - if (unpack_nameX(e, AA_STRUCT, "policydb")) { - /* generic policy dfa - optional and may be NULL */ - profile->policy.dfa = unpack_dfa(e); - if (IS_ERR(profile->policy.dfa)) { - error = PTR_ERR(profile->policy.dfa); - profile->policy.dfa = NULL; - 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; - } - - /* 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; - goto fail; - } - - if (!unpack_u32(e, &profile->file.start, "dfa_start")) - /* default start state */ - profile->file.start = DFA_START; - - if (!unpack_trans_table(e, profile)) - goto fail; - - if (!unpack_nameX(e, AA_STRUCTEND, NULL)) - goto fail; - - return profile; - -fail: - if (profile) - name = NULL; - else if (!name) - name = "unknown"; - audit_iface(profile, name, "failed to unpack profile", e, error); - aa_put_profile(profile); - - return ERR_PTR(error); -} - -/** - * verify_head - unpack serialized stream header - * @e: serialized data read head (NOT NULL) - * @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, const char **ns) -{ - int error = -EPROTONOSUPPORT; - /* get the interface version */ - if (!unpack_u32(e, &e->version, "version")) { - audit_iface(NULL, NULL, "invalid profile format", e, error); - return error; - } - - /* check that the interface version is currently supported */ - if (e->version != 5) { - audit_iface(NULL, NULL, "unsupported interface version", e, - error); - return error; - } - - /* read the namespace if present */ - if (!unpack_str(e, ns, "namespace")) - *ns = NULL; - - 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 0; - return 1; -} - -/* 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 0; - if (!verify_xindex(dfa_other_xindex(dfa, i), table_size)) - return 0; - } - return 1; -} - -/** - * 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 (aa_g_paranoid_load) { - if (profile->file.dfa && - !verify_dfa_xindex(profile->file.dfa, - profile->file.trans.size)) { - audit_iface(profile, NULL, "Invalid named transition", - NULL, -EPROTO); - return -EPROTO; - } - } - - return 0; -} - -/** - * aa_unpack - unpack packed binary profile data loaded from user space - * @udata: user data copied to kmem (NOT NULL) - * @size: the size of the user data - * @ns: Returns namespace profile is in if specified else NULL (NOT NULL) - * - * Unpack user data and return refcounted allocated profile or ERR_PTR - * - * Returns: profile else error pointer if fails to unpack - */ -struct aa_profile *aa_unpack(void *udata, size_t size, const char **ns) -{ - struct aa_profile *profile = NULL; - int error; - struct aa_ext e = { - .start = udata, - .end = udata + size, - .pos = udata, - }; - - error = verify_header(&e, ns); - if (error) - return ERR_PTR(error); - - profile = unpack_profile(&e); - if (IS_ERR(profile)) - return profile; - - error = verify_profile(profile); - if (error) { - aa_put_profile(profile); - profile = ERR_PTR(error); - } - - /* return refcount */ - return profile; -} |