Revision 6fd4b15603124c1b56e03db29b41ec39d8a077b9 authored by Steve Cornelius on 15 June 2015, 23:52:56 UTC, committed by Herbert Xu on 16 June 2015, 06:20:38 UTC
Multiple function in asynchronous hashing use a saved-state block, a.k.a. struct caam_hash_state, which holds a stash of information between requests (init/update/final). Certain values in this state block are loaded for processing using an inline-if, and when this is done, the potential for uninitialized data can pose conflicts. Therefore, this patch improves initialization of state data to prevent false assignments using uninitialized data in the state block. This patch addresses the following traceback, originating in ahash_final_ctx(), although a problem like this could certainly exhibit other symptoms: kernel BUG at arch/arm/mm/dma-mapping.c:465! Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = 80004000 [00000000] *pgd=00000000 Internal error: Oops: 805 [#1] PREEMPT SMP Modules linked in: CPU: 0 Not tainted (3.0.15-01752-gdd441b9-dirty #40) PC is at __bug+0x1c/0x28 LR is at __bug+0x18/0x28 pc : [<80043240>] lr : [<8004323c>] psr: 60000013 sp : e423fd98 ip : 60000013 fp : 0000001c r10: e4191b84 r9 : 00000020 r8 : 00000009 r7 : 88005038 r6 : 00000001 r5 : 2d676572 r4 : e4191a60 r3 : 00000000 r2 : 00000001 r1 : 60000093 r0 : 00000033 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel Control: 10c53c7d Table: 1000404a DAC: 00000015 Process cryptomgr_test (pid: 1306, stack limit = 0xe423e2f0) Stack: (0xe423fd98 to 0xe4240000) fd80: 11807fd1 80048544 fda0: 88005000 e4191a00 e5178040 8039dda0 00000000 00000014 2d676572 e4191008 fdc0: 88005018 e4191a60 00100100 e4191a00 00000000 8039ce0c e423fea8 00000007 fde0: e4191a00 e4227000 e5178000 8039ce18 e419183c 80203808 80a94a44 00000006 fe00: 00000000 80207180 00000000 00000006 e423ff08 00000000 00000007 e5178000 fe20: e41918a4 80a949b4 8c4844e2 00000000 00000049 74227000 8c4844e2 00000e90 fe40: 0000000e 74227e90 ffff8c58 80ac29e0 e423fed4 8006a350 8c81625c e423ff5c fe60: 00008576 e4002500 00000003 00030010 e4002500 00000003 e5180000 e4002500 fe80: e5178000 800e6d24 007fffff 00000000 00000010 e4001280 e4002500 60000013 fea0: 000000d0 804df078 00000000 00000000 00000000 00000000 00000000 00000000 fec0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 fee0: 00000000 00000000 e4227000 e4226000 e4753000 e4752000 e40a5000 e40a4000 ff00: e41e7000 e41e6000 00000000 00000000 00000000 e423ff14 e423ff14 00000000 ff20: 00000400 804f9080 e5178000 e4db0b40 00000000 e4db0b80 0000047c 00000400 ff40: 00000000 8020758c 00000400 ffffffff 0000008a 00000000 e4db0b40 80206e00 ff60: e4049dbc 00000000 00000000 00000003 e423ffa4 80062978 e41a8bfc 00000000 ff80: 00000000 e4049db4 00000013 e4049db0 00000013 00000000 00000000 00000000 ffa0: e4db0b40 e4db0b40 80204cbc 00000013 00000000 00000000 00000000 80204cfc ffc0: e4049da0 80089544 80040a40 00000000 e4db0b40 00000000 00000000 00000000 ffe0: e423ffe0 e423ffe0 e4049da0 800894c4 80040a40 80040a40 00000000 00000000 [<80043240>] (__bug+0x1c/0x28) from [<80048544>] (___dma_single_dev_to_cpu+0x84) [<80048544>] (___dma_single_dev_to_cpu+0x84/0x94) from [<8039dda0>] (ahash_fina) [<8039dda0>] (ahash_final_ctx+0x180/0x428) from [<8039ce18>] (ahash_final+0xc/0) [<8039ce18>] (ahash_final+0xc/0x10) from [<80203808>] (crypto_ahash_op+0x28/0xc) [<80203808>] (crypto_ahash_op+0x28/0xc0) from [<80207180>] (test_hash+0x214/0x5) [<80207180>] (test_hash+0x214/0x5b8) from [<8020758c>] (alg_test_hash+0x68/0x8c) [<8020758c>] (alg_test_hash+0x68/0x8c) from [<80206e00>] (alg_test+0x7c/0x1b8) [<80206e00>] (alg_test+0x7c/0x1b8) from [<80204cfc>] (cryptomgr_test+0x40/0x48) [<80204cfc>] (cryptomgr_test+0x40/0x48) from [<80089544>] (kthread+0x80/0x88) [<80089544>] (kthread+0x80/0x88) from [<80040a40>] (kernel_thread_exit+0x0/0x8) Code: e59f0010 e1a01003 eb126a8d e3a03000 (e5833000) ---[ end trace d52a403a1d1eaa86 ]--- Cc: stable@vger.kernel.org Signed-off-by: Steve Cornelius <steve.cornelius@freescale.com> Signed-off-by: Victoria Milhoan <vicki.milhoan@freescale.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
1 parent f858c7b
audit_watch.c
/* audit_watch.c -- watching inodes
*
* Copyright 2003-2009 Red Hat, Inc.
* Copyright 2005 Hewlett-Packard Development Company, L.P.
* Copyright 2005 IBM Corporation
*
* 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; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/kernel.h>
#include <linux/audit.h>
#include <linux/kthread.h>
#include <linux/mutex.h>
#include <linux/fs.h>
#include <linux/fsnotify_backend.h>
#include <linux/namei.h>
#include <linux/netlink.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/security.h>
#include "audit.h"
/*
* Reference counting:
*
* audit_parent: lifetime is from audit_init_parent() to receipt of an FS_IGNORED
* event. Each audit_watch holds a reference to its associated parent.
*
* audit_watch: if added to lists, lifetime is from audit_init_watch() to
* audit_remove_watch(). Additionally, an audit_watch may exist
* temporarily to assist in searching existing filter data. Each
* audit_krule holds a reference to its associated watch.
*/
struct audit_watch {
atomic_t count; /* reference count */
dev_t dev; /* associated superblock device */
char *path; /* insertion path */
unsigned long ino; /* associated inode number */
struct audit_parent *parent; /* associated parent */
struct list_head wlist; /* entry in parent->watches list */
struct list_head rules; /* anchor for krule->rlist */
};
struct audit_parent {
struct list_head watches; /* anchor for audit_watch->wlist */
struct fsnotify_mark mark; /* fsnotify mark on the inode */
};
/* fsnotify handle. */
static struct fsnotify_group *audit_watch_group;
/* fsnotify events we care about. */
#define AUDIT_FS_WATCH (FS_MOVE | FS_CREATE | FS_DELETE | FS_DELETE_SELF |\
FS_MOVE_SELF | FS_EVENT_ON_CHILD)
static void audit_free_parent(struct audit_parent *parent)
{
WARN_ON(!list_empty(&parent->watches));
kfree(parent);
}
static void audit_watch_free_mark(struct fsnotify_mark *entry)
{
struct audit_parent *parent;
parent = container_of(entry, struct audit_parent, mark);
audit_free_parent(parent);
}
static void audit_get_parent(struct audit_parent *parent)
{
if (likely(parent))
fsnotify_get_mark(&parent->mark);
}
static void audit_put_parent(struct audit_parent *parent)
{
if (likely(parent))
fsnotify_put_mark(&parent->mark);
}
/*
* Find and return the audit_parent on the given inode. If found a reference
* is taken on this parent.
*/
static inline struct audit_parent *audit_find_parent(struct inode *inode)
{
struct audit_parent *parent = NULL;
struct fsnotify_mark *entry;
entry = fsnotify_find_inode_mark(audit_watch_group, inode);
if (entry)
parent = container_of(entry, struct audit_parent, mark);
return parent;
}
void audit_get_watch(struct audit_watch *watch)
{
atomic_inc(&watch->count);
}
void audit_put_watch(struct audit_watch *watch)
{
if (atomic_dec_and_test(&watch->count)) {
WARN_ON(watch->parent);
WARN_ON(!list_empty(&watch->rules));
kfree(watch->path);
kfree(watch);
}
}
static void audit_remove_watch(struct audit_watch *watch)
{
list_del(&watch->wlist);
audit_put_parent(watch->parent);
watch->parent = NULL;
audit_put_watch(watch); /* match initial get */
}
char *audit_watch_path(struct audit_watch *watch)
{
return watch->path;
}
int audit_watch_compare(struct audit_watch *watch, unsigned long ino, dev_t dev)
{
return (watch->ino != (unsigned long)-1) &&
(watch->ino == ino) &&
(watch->dev == dev);
}
/* Initialize a parent watch entry. */
static struct audit_parent *audit_init_parent(struct path *path)
{
struct inode *inode = path->dentry->d_inode;
struct audit_parent *parent;
int ret;
parent = kzalloc(sizeof(*parent), GFP_KERNEL);
if (unlikely(!parent))
return ERR_PTR(-ENOMEM);
INIT_LIST_HEAD(&parent->watches);
fsnotify_init_mark(&parent->mark, audit_watch_free_mark);
parent->mark.mask = AUDIT_FS_WATCH;
ret = fsnotify_add_mark(&parent->mark, audit_watch_group, inode, NULL, 0);
if (ret < 0) {
audit_free_parent(parent);
return ERR_PTR(ret);
}
return parent;
}
/* Initialize a watch entry. */
static struct audit_watch *audit_init_watch(char *path)
{
struct audit_watch *watch;
watch = kzalloc(sizeof(*watch), GFP_KERNEL);
if (unlikely(!watch))
return ERR_PTR(-ENOMEM);
INIT_LIST_HEAD(&watch->rules);
atomic_set(&watch->count, 1);
watch->path = path;
watch->dev = (dev_t)-1;
watch->ino = (unsigned long)-1;
return watch;
}
/* Translate a watch string to kernel respresentation. */
int audit_to_watch(struct audit_krule *krule, char *path, int len, u32 op)
{
struct audit_watch *watch;
if (!audit_watch_group)
return -EOPNOTSUPP;
if (path[0] != '/' || path[len-1] == '/' ||
krule->listnr != AUDIT_FILTER_EXIT ||
op != Audit_equal ||
krule->inode_f || krule->watch || krule->tree)
return -EINVAL;
watch = audit_init_watch(path);
if (IS_ERR(watch))
return PTR_ERR(watch);
audit_get_watch(watch);
krule->watch = watch;
return 0;
}
/* Duplicate the given audit watch. The new watch's rules list is initialized
* to an empty list and wlist is undefined. */
static struct audit_watch *audit_dupe_watch(struct audit_watch *old)
{
char *path;
struct audit_watch *new;
path = kstrdup(old->path, GFP_KERNEL);
if (unlikely(!path))
return ERR_PTR(-ENOMEM);
new = audit_init_watch(path);
if (IS_ERR(new)) {
kfree(path);
goto out;
}
new->dev = old->dev;
new->ino = old->ino;
audit_get_parent(old->parent);
new->parent = old->parent;
out:
return new;
}
static void audit_watch_log_rule_change(struct audit_krule *r, struct audit_watch *w, char *op)
{
if (audit_enabled) {
struct audit_buffer *ab;
ab = audit_log_start(NULL, GFP_NOFS, AUDIT_CONFIG_CHANGE);
if (unlikely(!ab))
return;
audit_log_format(ab, "auid=%u ses=%u op=",
from_kuid(&init_user_ns, audit_get_loginuid(current)),
audit_get_sessionid(current));
audit_log_string(ab, op);
audit_log_format(ab, " path=");
audit_log_untrustedstring(ab, w->path);
audit_log_key(ab, r->filterkey);
audit_log_format(ab, " list=%d res=1", r->listnr);
audit_log_end(ab);
}
}
/* Update inode info in audit rules based on filesystem event. */
static void audit_update_watch(struct audit_parent *parent,
const char *dname, dev_t dev,
unsigned long ino, unsigned invalidating)
{
struct audit_watch *owatch, *nwatch, *nextw;
struct audit_krule *r, *nextr;
struct audit_entry *oentry, *nentry;
mutex_lock(&audit_filter_mutex);
/* Run all of the watches on this parent looking for the one that
* matches the given dname */
list_for_each_entry_safe(owatch, nextw, &parent->watches, wlist) {
if (audit_compare_dname_path(dname, owatch->path,
AUDIT_NAME_FULL))
continue;
/* If the update involves invalidating rules, do the inode-based
* filtering now, so we don't omit records. */
if (invalidating && !audit_dummy_context())
audit_filter_inodes(current, current->audit_context);
/* updating ino will likely change which audit_hash_list we
* are on so we need a new watch for the new list */
nwatch = audit_dupe_watch(owatch);
if (IS_ERR(nwatch)) {
mutex_unlock(&audit_filter_mutex);
audit_panic("error updating watch, skipping");
return;
}
nwatch->dev = dev;
nwatch->ino = ino;
list_for_each_entry_safe(r, nextr, &owatch->rules, rlist) {
oentry = container_of(r, struct audit_entry, rule);
list_del(&oentry->rule.rlist);
list_del_rcu(&oentry->list);
nentry = audit_dupe_rule(&oentry->rule);
if (IS_ERR(nentry)) {
list_del(&oentry->rule.list);
audit_panic("error updating watch, removing");
} else {
int h = audit_hash_ino((u32)ino);
/*
* nentry->rule.watch == oentry->rule.watch so
* we must drop that reference and set it to our
* new watch.
*/
audit_put_watch(nentry->rule.watch);
audit_get_watch(nwatch);
nentry->rule.watch = nwatch;
list_add(&nentry->rule.rlist, &nwatch->rules);
list_add_rcu(&nentry->list, &audit_inode_hash[h]);
list_replace(&oentry->rule.list,
&nentry->rule.list);
}
audit_watch_log_rule_change(r, owatch, "updated_rules");
call_rcu(&oentry->rcu, audit_free_rule_rcu);
}
audit_remove_watch(owatch);
goto add_watch_to_parent; /* event applies to a single watch */
}
mutex_unlock(&audit_filter_mutex);
return;
add_watch_to_parent:
list_add(&nwatch->wlist, &parent->watches);
mutex_unlock(&audit_filter_mutex);
return;
}
/* Remove all watches & rules associated with a parent that is going away. */
static void audit_remove_parent_watches(struct audit_parent *parent)
{
struct audit_watch *w, *nextw;
struct audit_krule *r, *nextr;
struct audit_entry *e;
mutex_lock(&audit_filter_mutex);
list_for_each_entry_safe(w, nextw, &parent->watches, wlist) {
list_for_each_entry_safe(r, nextr, &w->rules, rlist) {
e = container_of(r, struct audit_entry, rule);
audit_watch_log_rule_change(r, w, "remove_rule");
list_del(&r->rlist);
list_del(&r->list);
list_del_rcu(&e->list);
call_rcu(&e->rcu, audit_free_rule_rcu);
}
audit_remove_watch(w);
}
mutex_unlock(&audit_filter_mutex);
fsnotify_destroy_mark(&parent->mark, audit_watch_group);
}
/* Get path information necessary for adding watches. */
static int audit_get_nd(struct audit_watch *watch, struct path *parent)
{
struct dentry *d = kern_path_locked(watch->path, parent);
if (IS_ERR(d))
return PTR_ERR(d);
mutex_unlock(&parent->dentry->d_inode->i_mutex);
if (d->d_inode) {
/* update watch filter fields */
watch->dev = d->d_inode->i_sb->s_dev;
watch->ino = d->d_inode->i_ino;
}
dput(d);
return 0;
}
/* Associate the given rule with an existing parent.
* Caller must hold audit_filter_mutex. */
static void audit_add_to_parent(struct audit_krule *krule,
struct audit_parent *parent)
{
struct audit_watch *w, *watch = krule->watch;
int watch_found = 0;
BUG_ON(!mutex_is_locked(&audit_filter_mutex));
list_for_each_entry(w, &parent->watches, wlist) {
if (strcmp(watch->path, w->path))
continue;
watch_found = 1;
/* put krule's and initial refs to temporary watch */
audit_put_watch(watch);
audit_put_watch(watch);
audit_get_watch(w);
krule->watch = watch = w;
break;
}
if (!watch_found) {
audit_get_parent(parent);
watch->parent = parent;
list_add(&watch->wlist, &parent->watches);
}
list_add(&krule->rlist, &watch->rules);
}
/* Find a matching watch entry, or add this one.
* Caller must hold audit_filter_mutex. */
int audit_add_watch(struct audit_krule *krule, struct list_head **list)
{
struct audit_watch *watch = krule->watch;
struct audit_parent *parent;
struct path parent_path;
int h, ret = 0;
mutex_unlock(&audit_filter_mutex);
/* Avoid calling path_lookup under audit_filter_mutex. */
ret = audit_get_nd(watch, &parent_path);
/* caller expects mutex locked */
mutex_lock(&audit_filter_mutex);
if (ret)
return ret;
/* either find an old parent or attach a new one */
parent = audit_find_parent(parent_path.dentry->d_inode);
if (!parent) {
parent = audit_init_parent(&parent_path);
if (IS_ERR(parent)) {
ret = PTR_ERR(parent);
goto error;
}
}
audit_add_to_parent(krule, parent);
/* match get in audit_find_parent or audit_init_parent */
audit_put_parent(parent);
h = audit_hash_ino((u32)watch->ino);
*list = &audit_inode_hash[h];
error:
path_put(&parent_path);
return ret;
}
void audit_remove_watch_rule(struct audit_krule *krule)
{
struct audit_watch *watch = krule->watch;
struct audit_parent *parent = watch->parent;
list_del(&krule->rlist);
if (list_empty(&watch->rules)) {
audit_remove_watch(watch);
if (list_empty(&parent->watches)) {
audit_get_parent(parent);
fsnotify_destroy_mark(&parent->mark, audit_watch_group);
audit_put_parent(parent);
}
}
}
/* Update watch data in audit rules based on fsnotify events. */
static int audit_watch_handle_event(struct fsnotify_group *group,
struct inode *to_tell,
struct fsnotify_mark *inode_mark,
struct fsnotify_mark *vfsmount_mark,
u32 mask, void *data, int data_type,
const unsigned char *dname, u32 cookie)
{
struct inode *inode;
struct audit_parent *parent;
parent = container_of(inode_mark, struct audit_parent, mark);
BUG_ON(group != audit_watch_group);
switch (data_type) {
case (FSNOTIFY_EVENT_PATH):
inode = ((struct path *)data)->dentry->d_inode;
break;
case (FSNOTIFY_EVENT_INODE):
inode = (struct inode *)data;
break;
default:
BUG();
inode = NULL;
break;
};
if (mask & (FS_CREATE|FS_MOVED_TO) && inode)
audit_update_watch(parent, dname, inode->i_sb->s_dev, inode->i_ino, 0);
else if (mask & (FS_DELETE|FS_MOVED_FROM))
audit_update_watch(parent, dname, (dev_t)-1, (unsigned long)-1, 1);
else if (mask & (FS_DELETE_SELF|FS_UNMOUNT|FS_MOVE_SELF))
audit_remove_parent_watches(parent);
return 0;
}
static const struct fsnotify_ops audit_watch_fsnotify_ops = {
.handle_event = audit_watch_handle_event,
};
static int __init audit_watch_init(void)
{
audit_watch_group = fsnotify_alloc_group(&audit_watch_fsnotify_ops);
if (IS_ERR(audit_watch_group)) {
audit_watch_group = NULL;
audit_panic("cannot create audit fsnotify group");
}
return 0;
}
device_initcall(audit_watch_init);
![swh spinner](/static/img/swh-spinner.gif)
Computing file changes ...