Messages in this thread Patch in this message | | | Subject | [PATCH] klist: del waiter from klist_remove_waiters before wakeup waitting process | From | wangbiao <> | Date | Fri, 03 May 2013 15:06:36 +0800 |
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From: "wang, biao" <biao.wang@intel.com> Date: Fri, 3 May 2013 14:18:34 +0800 Subject: [PATCH] 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> --- lib/klist.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/lib/klist.c b/lib/klist.c index 0874e41..358a368 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); -- 1.7.6
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