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| author | Sasha Levin <levinsasha928@gmail.com> | 2012-04-25 16:01:53 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-04-25 21:26:34 -0700 |
| commit | 6e8b09eaf268bceac0c62e389b4bc0cb83dfb8e5 (patch) | |
| tree | 8b284da8a79355ef631c8c418c369fd1ec83b251 /mm | |
| parent | f2a9ef880763d7fbd657a3af646e132a90d70d34 (diff) | |
| download | lwn-6e8b09eaf268bceac0c62e389b4bc0cb83dfb8e5.tar.gz lwn-6e8b09eaf268bceac0c62e389b4bc0cb83dfb8e5.zip | |
mm: fix NULL ptr dereference in move_pages
Commit 3268c63 ("mm: fix move/migrate_pages() race on task struct") has
added an odd construct where 'mm' is checked for being NULL, and if it is,
it would get dereferenced anyways by mput()ing it.
Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Acked-by: Christoph Lameter <cl@linux.com>
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.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/mm/migrate.c b/mm/migrate.c index 51c08a0c6f68..11072383ae12 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1388,14 +1388,14 @@ SYSCALL_DEFINE6(move_pages, pid_t, pid, unsigned long, nr_pages, mm = get_task_mm(task); put_task_struct(task); - if (mm) { - if (nodes) - err = do_pages_move(mm, task_nodes, nr_pages, pages, - nodes, status, flags); - else - err = do_pages_stat(mm, nr_pages, pages, status); - } else - err = -EINVAL; + if (!mm) + return -EINVAL; + + if (nodes) + err = do_pages_move(mm, task_nodes, nr_pages, pages, + nodes, status, flags); + else + err = do_pages_stat(mm, nr_pages, pages, status); mmput(mm); return err; |