mm: avoid null-pointer deref in sync_mm_rss()
authorKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Tue, 6 Apr 2010 21:34:42 +0000 (14:34 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 7 Apr 2010 15:38:02 +0000 (08:38 -0700)
commita3a2e76c77fa22b114e421ac11dec0c56c3503fb
treecc67bbd8d5d364e55ea7a00d0b5ad68d5eac08ac
parentb01d0942c2b7a3026d2b7d38b5773d3d00420e06
mm: avoid null-pointer deref in sync_mm_rss()

- We weren't zeroing p->rss_stat[] at fork()

- Consequently sync_mm_rss() was dereferencing tsk->mm for kernel
  threads and was oopsing.

- Make __sync_task_rss_stat() static, too.

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=15648

[akpm@linux-foundation.org: remove the BUG_ON(!mm->rss)]
Reported-by: Troels Liebe Bentsen <tlb@rapanden.dk>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
"Michael S. Tsirkin" <mst@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kernel/exit.c
kernel/fork.c
mm/memory.c