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From: Sasha Levin <sashal@kernel.org>
To: stable@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Eric Dumazet <edumazet@google.com>,
	Dmitry Torokhov <dmitry.torokhov@gmail.com>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH AUTOSEL 4.9 2/9] Input: mousedev - add a schedule point in mousedev_write()
Date: Mon, 22 Oct 2018 06:21:26 -0400	[thread overview]
Message-ID: <20181022102133.41222-2-sashal@kernel.org> (raw)
In-Reply-To: <20181022102133.41222-1-sashal@kernel.org>

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);
-- 
2.17.1

  reply	other threads:[~2018-10-22 10:21 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-22 10:21 [PATCH AUTOSEL 4.9 1/9] ARM: dts: imx53-qsb: disable 1.2GHz OPP Sasha Levin
2018-10-22 10:21 ` Sasha Levin [this message]
2018-10-22 10:21 ` [PATCH AUTOSEL 4.9 3/9] Input: evdev - add a schedule point in evdev_write() Sasha Levin
2018-10-22 10:21 ` [PATCH AUTOSEL 4.9 4/9] Input: uinput - add a schedule point in uinput_inject_events() Sasha Levin
2018-10-22 10:21 ` [PATCH AUTOSEL 4.9 5/9] rxrpc: Don't check RXRPC_CALL_TX_LAST after calling rxrpc_rotate_tx_window() Sasha Levin
2018-10-22 10:21 ` [PATCH AUTOSEL 4.9 6/9] rxrpc: Only take the rwind and mtu values from latest ACK Sasha Levin
2018-10-22 10:21 ` [PATCH AUTOSEL 4.9 7/9] net: ena: fix NULL dereference due to untimely napi initialization Sasha Levin
2018-10-22 10:21 ` [PATCH AUTOSEL 4.9 8/9] libertas: call into generic suspend code before turning off power Sasha Levin
2018-10-22 10:21 ` [PATCH AUTOSEL 4.9 9/9] fs/fat/fatent.c: add cond_resched() to fat_count_free_clusters() Sasha Levin

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