Return-Path: From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Eric Dumazet , Dmitry Torokhov , Sasha Levin Subject: [PATCH AUTOSEL 3.18 1/4] Input: mousedev - add a schedule point in mousedev_write() Date: Mon, 22 Oct 2018 06:22:52 -0400 Message-Id: <20181022102255.41695-1-sashal@kernel.org> List-ID: From: Eric Dumazet [ 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 Reported-by: syzbot+9436b02171ac0894d33e@syzkaller.appspotmail.com Reviewed-by: Paul E. McKenney Signed-off-by: Dmitry Torokhov Signed-off-by: Sasha Levin --- 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