diff options
| author | KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> | 2009-11-11 14:26:26 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-11-12 07:25:56 -0800 |
| commit | e00e431612c3a6e437a01f2129fd3843da0c982a (patch) | |
| tree | 4f838123d0b295ab3608380ce803c8960a8ebfd0 /mm/migrate.c | |
| parent | b9f9d4706cb1b706f89f98ea6ead41ebecdefbc2 (diff) | |
| download | lwn-e00e431612c3a6e437a01f2129fd3843da0c982a.tar.gz lwn-e00e431612c3a6e437a01f2129fd3843da0c982a.zip | |
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/migrate.c')
| -rw-r--r-- | mm/migrate.c | 2 |
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; |