diff options
| author | Catalin Marinas <[email protected]> | 2016-10-27 17:46:47 -0700 |
|---|---|---|
| committer | Linus Torvalds <[email protected]> | 2016-10-27 18:43:43 -0700 |
| commit | 37df49f433bc3a11f5716fe65aaec5189c6402cb (patch) | |
| tree | 60265296d843c73e11f962bdf7560f0bb2bad43c | |
| parent | 02754e0a484a50a92d44c38879f2cb2792ebc572 (diff) | |
mm: kmemleak: ensure that the task stack is not freed during scanning
Commit 68f24b08ee89 ("sched/core: Free the stack early if
CONFIG_THREAD_INFO_IN_TASK") may cause the task->stack to be freed
during kmemleak_scan() execution, leading to either a NULL pointer fault
(if task->stack is NULL) or kmemleak accessing already freed memory.
This patch uses the new try_get_task_stack() API to ensure that the task
stack is not freed during kmemleak stack scanning.
Addresses https://bugzilla.kernel.org/show_bug.cgi?id=173901.
Fixes: 68f24b08ee89 ("sched/core: Free the stack early if CONFIG_THREAD_INFO_IN_TASK")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Catalin Marinas <[email protected]>
Reported-by: CAI Qian <[email protected]>
Tested-by: CAI Qian <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: CAI Qian <[email protected]>
Cc: Hillf Danton <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
| -rw-r--r-- | mm/kmemleak.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/mm/kmemleak.c b/mm/kmemleak.c index a5e453cf05c4..e5355a5b423f 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -1453,8 +1453,11 @@ static void kmemleak_scan(void) read_lock(&tasklist_lock); do_each_thread(g, p) { - scan_block(task_stack_page(p), task_stack_page(p) + - THREAD_SIZE, NULL); + void *stack = try_get_task_stack(p); + if (stack) { + scan_block(stack, stack + THREAD_SIZE, NULL); + put_task_stack(p); + } } while_each_thread(g, p); read_unlock(&tasklist_lock); } |