linux/security/apparmor/policy_unpack.c

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/*
* 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 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 "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 (aa_g_hash_policy && memcmp(l->hash, r->hash, aa_hash_size()) != 0)
return false;
return memcmp(l->data, r->data, 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) {
apparmor: fix possible recursive lock warning in __aa_create_ns Use mutex_lock_nested to provide lockdep the parent child lock ordering of the tree. This fixes the lockdep Warning [ 305.275177] ============================================ [ 305.275178] WARNING: possible recursive locking detected [ 305.275179] 4.14.0-rc7+ #320 Not tainted [ 305.275180] -------------------------------------------- [ 305.275181] apparmor_parser/1339 is trying to acquire lock: [ 305.275182] (&ns->lock){+.+.}, at: [<ffffffff970544dd>] __aa_create_ns+0x6d/0x1e0 [ 305.275187] but task is already holding lock: [ 305.275187] (&ns->lock){+.+.}, at: [<ffffffff97054b5d>] aa_prepare_ns+0x3d/0xd0 [ 305.275190] other info that might help us debug this: [ 305.275191] Possible unsafe locking scenario: [ 305.275192] CPU0 [ 305.275193] ---- [ 305.275193] lock(&ns->lock); [ 305.275194] lock(&ns->lock); [ 305.275195] *** DEADLOCK *** [ 305.275196] May be due to missing lock nesting notation [ 305.275198] 2 locks held by apparmor_parser/1339: [ 305.275198] #0: (sb_writers#10){.+.+}, at: [<ffffffff96e9c6b7>] vfs_write+0x1a7/0x1d0 [ 305.275202] #1: (&ns->lock){+.+.}, at: [<ffffffff97054b5d>] aa_prepare_ns+0x3d/0xd0 [ 305.275205] stack backtrace: [ 305.275207] CPU: 1 PID: 1339 Comm: apparmor_parser Not tainted 4.14.0-rc7+ #320 [ 305.275208] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.1-1ubuntu1 04/01/2014 [ 305.275209] Call Trace: [ 305.275212] dump_stack+0x85/0xcb [ 305.275214] __lock_acquire+0x141c/0x1460 [ 305.275216] ? __aa_create_ns+0x6d/0x1e0 [ 305.275218] ? ___slab_alloc+0x183/0x540 [ 305.275219] ? ___slab_alloc+0x183/0x540 [ 305.275221] lock_acquire+0xed/0x1e0 [ 305.275223] ? lock_acquire+0xed/0x1e0 [ 305.275224] ? __aa_create_ns+0x6d/0x1e0 [ 305.275227] __mutex_lock+0x89/0x920 [ 305.275228] ? __aa_create_ns+0x6d/0x1e0 [ 305.275230] ? trace_hardirqs_on_caller+0x11f/0x190 [ 305.275231] ? __aa_create_ns+0x6d/0x1e0 [ 305.275233] ? __lockdep_init_map+0x57/0x1d0 [ 305.275234] ? lockdep_init_map+0x9/0x10 [ 305.275236] ? __rwlock_init+0x32/0x60 [ 305.275238] mutex_lock_nested+0x1b/0x20 [ 305.275240] ? mutex_lock_nested+0x1b/0x20 [ 305.275241] __aa_create_ns+0x6d/0x1e0 [ 305.275243] aa_prepare_ns+0xc2/0xd0 [ 305.275245] aa_replace_profiles+0x168/0xf30 [ 305.275247] ? __might_fault+0x85/0x90 [ 305.275250] policy_update+0xb9/0x380 [ 305.275252] profile_load+0x7e/0x90 [ 305.275254] __vfs_write+0x28/0x150 [ 305.275256] ? rcu_read_lock_sched_held+0x72/0x80 [ 305.275257] ? rcu_sync_lockdep_assert+0x2f/0x60 [ 305.275259] ? __sb_start_write+0xdc/0x1c0 [ 305.275261] ? vfs_write+0x1a7/0x1d0 [ 305.275262] vfs_write+0xca/0x1d0 [ 305.275264] ? trace_hardirqs_on_caller+0x11f/0x190 [ 305.275266] SyS_write+0x49/0xa0 [ 305.275268] entry_SYSCALL_64_fastpath+0x23/0xc2 [ 305.275271] RIP: 0033:0x7fa6b22e8c74 [ 305.275272] RSP: 002b:00007ffeaaee6288 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 305.275273] RAX: ffffffffffffffda RBX: 00007ffeaaee62a4 RCX: 00007fa6b22e8c74 [ 305.275274] RDX: 0000000000000a51 RSI: 00005566a8198c10 RDI: 0000000000000004 [ 305.275275] RBP: 0000000000000a39 R08: 0000000000000a51 R09: 0000000000000000 [ 305.275276] R10: 0000000000000000 R11: 0000000000000246 R12: 00005566a8198c10 [ 305.275277] R13: 0000000000000004 R14: 00005566a72ecb88 R15: 00005566a72ec3a8 Fixes: 73688d1ed0b8 ("apparmor: refactor prepare_ns() and make usable from different views") Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-11-21 08:24:09 +01:00
mutex_lock_nested(&ns->lock, ns->level);
__aa_fs_remove_rawdata(d);
mutex_unlock(&ns->lock);
aa_put_ns(ns);
}
kzfree(d->hash);
kzfree(d->name);
kvfree(d->data);
kzfree(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;
if (!inbounds(e, sizeof(u16)))
return 0;
size = le16_to_cpu(get_unaligned((__le16 *) e->pos));
e->pos += sizeof(__le16);
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_u8(struct aa_ext *e, u8 *data, const char *name)
{
if (unpack_nameX(e, AA_U8, name)) {
if (!inbounds(e, sizeof(u8)))
return 0;
if (data)
*data = get_unaligned((u8 *)e->pos);
e->pos += sizeof(u8);
return 1;
}
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((__le32 *) 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((__le64 *) 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((__le16 *) 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((__le32 *) 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;
}
/**
* 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: 1 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;
treewide: kzalloc() -> kcalloc() The kzalloc() function has a 2-factor argument form, kcalloc(). This patch replaces cases of: kzalloc(a * b, gfp) with: kcalloc(a * b, gfp) as well as handling cases of: kzalloc(a * b * c, gfp) with: kzalloc(array3_size(a, b, c), gfp) as it's slightly less ugly than: kzalloc_array(array_size(a, b), c, gfp) This does, however, attempt to ignore constant size factors like: kzalloc(4 * 1024, gfp) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( kzalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | kzalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( kzalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(char) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(u8) * COUNT + COUNT , ...) | kzalloc( - sizeof(__u8) * COUNT + COUNT , ...) | kzalloc( - sizeof(char) * COUNT + COUNT , ...) | kzalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( - kzalloc + kcalloc ( - sizeof(TYPE) * (COUNT_ID) + COUNT_ID, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * COUNT_ID + COUNT_ID, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * (COUNT_CONST) + COUNT_CONST, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * COUNT_CONST + COUNT_CONST, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * (COUNT_ID) + COUNT_ID, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * COUNT_ID + COUNT_ID, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * (COUNT_CONST) + COUNT_CONST, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * COUNT_CONST + COUNT_CONST, sizeof(THING) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ - kzalloc + kcalloc ( - SIZE * COUNT + COUNT, SIZE , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( kzalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kzalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kzalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kzalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( kzalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kzalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kzalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kzalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kzalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | kzalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( kzalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products, // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( kzalloc(C1 * C2 * C3, ...) | kzalloc( - (E1) * E2 * E3 + array3_size(E1, E2, E3) , ...) | kzalloc( - (E1) * (E2) * E3 + array3_size(E1, E2, E3) , ...) | kzalloc( - (E1) * (E2) * (E3) + array3_size(E1, E2, E3) , ...) | kzalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants, // keeping sizeof() as the second factor argument. @@ expression THING, E1, E2; type TYPE; constant C1, C2, C3; @@ ( kzalloc(sizeof(THING) * C2, ...) | kzalloc(sizeof(TYPE) * C2, ...) | kzalloc(C1 * C2 * C3, ...) | kzalloc(C1 * C2, ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * (E2) + E2, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * E2 + E2, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * (E2) + E2, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * E2 + E2, sizeof(THING) , ...) | - kzalloc + kcalloc ( - (E1) * E2 + E1, E2 , ...) | - kzalloc + kcalloc ( - (E1) * (E2) + E1, E2 , ...) | - kzalloc + kcalloc ( - E1 * E2 + E1, E2 , ...) ) Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-12 23:03:40 +02:00
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 1;
fail:
aa_free_domain_entries(&profile->file.trans);
e->pos = saved_pos;
return 0;
}
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 1;
fail:
e->pos = pos;
return 0;
}
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 1;
fail:
if (profile->secmark) {
for (i = 0; i < size; i++)
kfree(profile->secmark[i].label);
kfree(profile->secmark);
profile->secmark_count = 0;
}
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;
}
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_KILL)
profile->mode = APPARMOR_KILL;
else if (tmp == PACKED_MODE_UNCONFINED)
profile->mode = APPARMOR_UNCONFINED;
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, &params)) {
info = "failed to init key, value hash table";
goto fail;
}
while (unpack_strdup(e, &key, NULL)) {
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data) {
kzfree(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) {
kzfree(data->key);
kzfree(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 = name;
}
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 (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);
kzfree(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;
}
/**
* 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;
}
}
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;
}