From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: [PATCH] Input: mousedev - add a schedule point in mousedev_write() Date: Thu, 4 Oct 2018 08:47:49 -0700 Message-ID: <20181004154749.111595-1-edumazet@google.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: Sender: linux-kernel-owner@vger.kernel.org To: linux-kernel Cc: Eric Dumazet , Eric Dumazet , Dmitry Torokhov , linux-input@vger.kernel.org List-Id: linux-input@vger.kernel.org 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 Cc: Dmitry Torokhov Cc: linux-input@vger.kernel.org --- drivers/input/mousedev.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/input/mousedev.c b/drivers/input/mousedev.c index e08228061bcdd2f97aaadece31d6c83eb7539ae5..412fa71245afe26a7a8ad75705566f83633ba347 100644 --- a/drivers/input/mousedev.c +++ b/drivers/input/mousedev.c @@ -707,6 +707,7 @@ 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); -- 2.19.0.605.g01d371f741-goog