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authorKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>2009-11-12 01:26:26 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2009-11-12 18:25:56 +0300
commite00e431612c3a6e437a01f2129fd3843da0c982a (patch)
tree4f838123d0b295ab3608380ce803c8960a8ebfd0 /mm
parentb9f9d4706cb1b706f89f98ea6ead41ebecdefbc2 (diff)
downloadlinux-e00e431612c3a6e437a01f2129fd3843da0c982a.tar.xz
memcg: fix wrong pointer initialization at page migration when memcg is disabled.
Lee Schermerhorn reported that he saw bad pointer dereference in mem_cgroup_end_migration() when he disabled memcg by boot option. memcg's page migration logic works as mem_cgroup_prepare_migration(page, &ptr); do page migration mem_cgroup_end_migration(page, ptr); Now, ptr is not initialized in prepare_migration when memcg is disabled by boot option. This causes panic in end_migration. This patch fixes it. Reported-by: Lee Schermerhorn <Lee.Schermerhorn@hp.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/migrate.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/migrate.c b/mm/migrate.c
index 1a4bf4813780..7dbcb22316d2 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -602,7 +602,7 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private,
struct page *newpage = get_new_page(page, private, &result);
int rcu_locked = 0;
int charge = 0;
- struct mem_cgroup *mem;
+ struct mem_cgroup *mem = NULL;
if (!newpage)
return -ENOMEM;