From: Oleg Nesterov <oleg@redhat.com>
Date: Fri, 23 Apr 2010 17:18:01 +0000 (-0400)
Subject: rmap: anon_vma_prepare() can leak anon_vma_chain
X-Git-Tag: v2.6.34-rc6~42
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=31f2b0ebc01fd332cb0997f7ce9f9cde29af9e20;p=pandora-kernel.git

rmap: anon_vma_prepare() can leak anon_vma_chain

If find_mergeable_anon_vma() succeeds but another thread installs
->anon_vma before we take ptl, then allocated == NULL but avc should be
freed.  Change the code to check avc != NULL to detect this case.

Also, a couple of whitespace changes to make the critical section more
visible.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Pete Zaitcev <zaitcev@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

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