Messages in this thread Patch in this message | | | From | Sasha Levin <> | Subject | [PATCH 2/2] mm: fix NULL ptr dereference in move_pages | Date | Fri, 13 Apr 2012 08:58:22 -0400 |
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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> --- mm/migrate.c | 16 ++++++++-------- 1 files changed, 8 insertions(+), 8 deletions(-)
diff --git a/mm/migrate.c b/mm/migrate.c index 51c08a0..1107238 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; -- 1.7.8.5
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