From: Eric Dumazet edumazet@google.com
[ 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@google.com Reported-by: syzbot+9436b02171ac0894d33e@syzkaller.appspotmail.com Reviewed-by: Paul E. McKenney paulmck@linux.ibm.com Signed-off-by: Dmitry Torokhov dmitry.torokhov@gmail.com Signed-off-by: Sasha Levin sashal@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 30328e57fdda..b63eec7972e6 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);