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authorZqiang <qiang.zhang@windriver.com>2020-11-01 17:07:53 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-11-10 12:35:58 +0100
commit68e8b8ed787a8acafa3e987d52f6d415c5949ec6 (patch)
tree17ab44bd2a65088c4c5107397b0ecab2806f21f3 /kernel/kthread.c
parent1471e96263b6e68929e7afed28f80ab3b6bd1066 (diff)
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kthread_worker: prevent queuing delayed work from timer_fn when it is being canceled
commit 6993d0fdbee0eb38bfac350aa016f65ad11ed3b1 upstream. There is a small race window when a delayed work is being canceled and the work still might be queued from the timer_fn: CPU0 CPU1 kthread_cancel_delayed_work_sync() __kthread_cancel_work_sync() __kthread_cancel_work() work->canceling++; kthread_delayed_work_timer_fn() kthread_insert_work(); BUG: kthread_insert_work() should not get called when work->canceling is set. Signed-off-by: Zqiang <qiang.zhang@windriver.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20201014083030.16895-1-qiang.zhang@windriver.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/kthread.c')
-rw-r--r--kernel/kthread.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/kthread.c b/kernel/kthread.c
index b786eda90bb5..2eed853ab9cc 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -863,7 +863,8 @@ void kthread_delayed_work_timer_fn(struct timer_list *t)
/* Move the work from worker->delayed_work_list. */
WARN_ON_ONCE(list_empty(&work->node));
list_del_init(&work->node);
- kthread_insert_work(worker, work, &worker->work_list);
+ if (!work->canceling)
+ kthread_insert_work(worker, work, &worker->work_list);
spin_unlock(&worker->lock);
}