From b0a8cc58e6b9aaae3045752059e5e6260c0b94bc Mon Sep 17 00:00:00 2001 From: Takamori Yamaguchi <takamori.yamaguchi@jp.sony.com> Date: Thu, 8 Nov 2012 15:53:39 -0800 Subject: [PATCH] mm: bugfix: set current->reclaim_state to NULL while returning from kswapd() In kswapd(), set current->reclaim_state to NULL before returning, as current->reclaim_state holds reference to variable on kswapd()'s stack. In rare cases, while returning from kswapd() during memory offlining, __free_slab() and freepages() can access the dangling pointer of current->reclaim_state. Signed-off-by: Takamori Yamaguchi <takamori.yamaguchi@jp.sony.com> Signed-off-by: Aaditya Kumar <aaditya.kumar@ap.sony.com> Acked-by: David Rientjes <rientjes@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> --- mm/vmscan.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/vmscan.c b/mm/vmscan.c index 2624edcfb420..8b055e9379bc 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -3017,6 +3017,8 @@ static int kswapd(void *p) &balanced_classzone_idx); } } + + current->reclaim_state = NULL; return 0; } -- GitLab