summaryrefslogtreecommitdiff
path: root/mm
diff options
context:
space:
mode:
authorNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>2014-05-22 11:54:21 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-06-11 12:03:22 -0700
commit53e8565ac009becf0e27c2c77980426f1b40db09 (patch)
tree8fb5080e5d254d1b75ba3db2e9ef206fbb70f2fa /mm
parent509a6ce860fc71a16cdeed25b131c26d4917a0a6 (diff)
mm/memory-failure.c: fix memory leak by race between poison and unpoison
commit 3e030ecc0fc7de10fd0da10c1c19939872a31717 upstream. When a memory error happens on an in-use page or (free and in-use) hugepage, the victim page is isolated with its refcount set to one. When you try to unpoison it later, unpoison_memory() calls put_page() for it twice in order to bring the page back to free page pool (buddy or free hugepage list). However, if another memory error occurs on the page which we are unpoisoning, memory_failure() returns without releasing the refcount which was incremented in the same call at first, which results in memory leak and unconsistent num_poisoned_pages statistics. This patch fixes it. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/memory-failure.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 4254eb021583..4f8548abd6ee 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1153,6 +1153,8 @@ int memory_failure(unsigned long pfn, int trapno, int flags)
*/
if (!PageHWPoison(p)) {
printk(KERN_ERR "MCE %#lx: just unpoisoned\n", pfn);
+ atomic_long_sub(nr_pages, &num_poisoned_pages);
+ put_page(hpage);
res = 0;
goto out;
}