| From | Greg Kroah-Hartman <> | Subject | [ 21/44] klist: del waiter from klist_remove_waiters before wakeup waitting process | Date | Wed, 5 Jun 2013 14:12:19 -0700 |
| |
3.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: "wang, biao" <biao.wang@intel.com>
commit ac5a2962b02f57dea76d314ef2521a2170b28ab6 upstream.
There is a race between klist_remove and klist_release. klist_remove uses a local var waiter saved on stack. When klist_release calls wake_up_process(waiter->process) to wake up the waiter, waiter might run immediately and reuse the stack. Then, klist_release calls list_del(&waiter->list) to change previous wait data and cause prior waiter thread corrupt.
The patch fixes it against kernel 3.9.
Signed-off-by: wang, biao <biao.wang@intel.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- lib/klist.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/lib/klist.c +++ b/lib/klist.c @@ -193,10 +193,10 @@ static void klist_release(struct kref *k if (waiter->node != n) continue; + list_del(&waiter->list); waiter->woken = 1; mb(); wake_up_process(waiter->process); - list_del(&waiter->list); } spin_unlock(&klist_remove_lock); knode_set_klist(n, NULL);
|