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authorXiaotian Feng <xtfeng@gmail.com>2012-01-12 17:17:08 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-01-12 20:13:02 -0800
commita2ef990ab5a6705a356d146dd773a3b359787497 (patch)
tree5eda6856d7e7662cc0742752f28e7626d4707f5f /fs/proc
parentbccd17294a26b67a8a19aaa120e3eeaa7da49281 (diff)
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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.c2
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);