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| author | Xiaotian Feng <xtfeng@gmail.com> | 2012-01-12 17:17:08 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-01-12 20:13:02 -0800 |
| commit | a2ef990ab5a6705a356d146dd773a3b359787497 (patch) | |
| tree | 5eda6856d7e7662cc0742752f28e7626d4707f5f /fs/proc | |
| parent | bccd17294a26b67a8a19aaa120e3eeaa7da49281 (diff) | |
| download | linux-a2ef990ab5a6705a356d146dd773a3b359787497.tar.gz linux-a2ef990ab5a6705a356d146dd773a3b359787497.tar.bz2 linux-a2ef990ab5a6705a356d146dd773a3b359787497.zip | |
proc: fix null pointer deref in proc_pid_permission()
get_proc_task() can fail to search the task and return NULL,
put_task_struct() will then bomb the kernel with following oops:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
IP: [<ffffffff81217d34>] proc_pid_permission+0x64/0xe0
PGD 112075067 PUD 112814067 PMD 0
Oops: 0002 [#1] PREEMPT SMP
This is a regression introduced by commit 0499680a ("procfs: add hidepid=
and gid= mount options"). The kernel should return -ESRCH if
get_proc_task() failed.
Signed-off-by: Xiaotian Feng <dannyfeng@tencent.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Vasiliy Kulikov <segoon@openwall.com>
Cc: Stephen Wilson <wilsons@start.ca>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/proc')
| -rw-r--r-- | fs/proc/base.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index 8173dfd89cb2..5485a5388ecb 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -654,6 +654,8 @@ static int proc_pid_permission(struct inode *inode, int mask) bool has_perms; task = get_proc_task(inode); + if (!task) + return -ESRCH; has_perms = has_pid_permissions(pid, task, 1); put_task_struct(task); |