From 8dba474f034c322d96ada39cb20cac711d80dcb2 Mon Sep 17 00:00:00 2001 From: Jesper Juhl Date: Tue, 25 Jan 2011 15:07:24 -0800 Subject: [PATCH] mm/memcontrol.c: fix uninitialized variable use in mem_cgroup_move_parent() In mm/memcontrol.c::mem_cgroup_move_parent() there's a path that jumps to the 'put_back' label ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false, charge); if (ret || !parent) goto put_back; where we'll if (charge > PAGE_SIZE) compound_unlock_irqrestore(page, flags); but, we have not assigned anything to 'flags' at this point, nor have we called 'compound_lock_irqsave()' (which is what sets 'flags'). The 'put_back' label should be moved below the call to compound_unlock_irqrestore() as per this patch. Signed-off-by: Jesper Juhl Cc: Balbir Singh Cc: Daisuke Nishimura Cc: KAMEZAWA Hiroyuki Cc: Pavel Emelianov Cc: "Kirill A. Shutemov" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index db76ef726293..4fcf47a62550 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2292,9 +2292,10 @@ static int mem_cgroup_move_parent(struct page_cgroup *pc, ret = mem_cgroup_move_account(pc, child, parent, true, charge); if (ret) mem_cgroup_cancel_charge(parent, charge); -put_back: + if (charge > PAGE_SIZE) compound_unlock_irqrestore(page, flags); +put_back: putback_lru_page(page); put: put_page(page); -- 2.20.1