From: Eric Dumazet <edumazet@xxxxxxxxxx> [ Upstream commit f74c371fe72a4f820d287db8067683fb533e4ede ] syzbot was able to trigger rcu stalls by calling write() with large number of bytes. Add a cond_resched() in the loop to avoid this. Link: https://lkml.org/lkml/2018/8/23/1106 Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx> Reported-by: syzbot+9436b02171ac0894d33e@xxxxxxxxxxxxxxxxxxxxxxxxx Reviewed-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxx> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/input/mousedev.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/input/mousedev.c b/drivers/input/mousedev.c index b604564dec5c..036acf861496 100644 --- a/drivers/input/mousedev.c +++ b/drivers/input/mousedev.c @@ -701,6 +701,7 @@ static ssize_t mousedev_write(struct file *file, const char __user *buffer, mousedev_generate_response(client, c); spin_unlock_irq(&client->packet_lock); + cond_resched(); } kill_fasync(&client->fasync, SIGIO, POLL_IN); -- 2.17.1
