diff options
| author | wang, biao <biao.wang@intel.com> | 2013-05-16 09:50:13 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-05-21 10:16:39 -0700 |
| commit | ac5a2962b02f57dea76d314ef2521a2170b28ab6 (patch) | |
| tree | 07c5b125c8b80182fedd9fd74098b79647f7a08f | |
| parent | 97521978c5ea80857d4f4f74d4e1fc93721482cf (diff) | |
klist: del waiter from klist_remove_waiters before wakeup waitting process
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>
| -rw-r--r-- | lib/klist.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/lib/klist.c b/lib/klist.c index 0874e41609a6..358a368a2947 100644 --- a/lib/klist.c +++ b/lib/klist.c @@ -193,10 +193,10 @@ static void klist_release(struct kref *kref) 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); |