Doug / smarc-fsl-linux-kernel

Download as
Browse Code ยป

Commit a2ef990ab5a6705a356d146dd773a3b359787497

Authored by Xiaotian Feng
Committed by Linus Torvalds
1 parent bccd17294a
Exists in master and in 6 other branches imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-l5.0.0_1.0.0-ga

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>

Showing 1 changed file with 2 additions and 0 deletions Side-by-side Diff

... ... @@ -654,6 +654,8 @@
654 654 bool has_perms;
655 655  
656 656 task = get_proc_task(inode);
  657 + if (!task)
  658 + return -ESRCH;
657 659 has_perms = has_pid_permissions(pid, task, 1);
658 660 put_task_struct(task);
659 661