From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B1104C004D3 for ; Mon, 22 Oct 2018 10:22:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7801A208AE for ; Mon, 22 Oct 2018 10:22:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="rmrN7dWv" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7801A208AE Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728904AbeJVSkf (ORCPT ); Mon, 22 Oct 2018 14:40:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:51164 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728469AbeJVSke (ORCPT ); Mon, 22 Oct 2018 14:40:34 -0400 Received: from sasha-vm.mshome.net (unknown [167.98.65.38]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id AC7BD20898; Mon, 22 Oct 2018 10:22:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1540203759; bh=3FHGt6W2v/tllxLFwIZ/CkwwOULmCIGoTU+gKDzkDj0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rmrN7dWvm7yK9pMS7XCg57AcFAGArwAkToDVV+Q7W+H7CWKKbp2qIPFvmbdjcDSTK 170UhNn3IA4XrUwU6I89pFqGPHfk5mpjY1S06Be/cAuoAsznUBBMg3C7VGS+2Rl5RA xyIxSd0MVueFZ12g4PgAT0XoCHqRj+HhC6uYZrag= From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Eric Dumazet , Dmitry Torokhov , Sasha Levin Subject: [PATCH AUTOSEL 4.4 2/5] Input: mousedev - add a schedule point in mousedev_write() Date: Mon, 22 Oct 2018 06:22:29 -0400 Message-Id: <20181022102232.41527-2-sashal@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181022102232.41527-1-sashal@kernel.org> References: <20181022102232.41527-1-sashal@kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 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