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,URIBL_BLOCKED,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 142D6C67863 for ; Mon, 22 Oct 2018 10:23:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CCFBA2089C for ; Mon, 22 Oct 2018 10:23:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="OYqbEABq" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CCFBA2089C 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 S1729397AbeJVSk7 (ORCPT ); Mon, 22 Oct 2018 14:40:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:51638 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728604AbeJVSk7 (ORCPT ); Mon, 22 Oct 2018 14:40:59 -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 26A332089C; Mon, 22 Oct 2018 10:22:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1540203783; bh=4+QpwNejEyhKST9OuVCuWn5/RmoYMlqY86nZaE+2Q/I=; h=From:To:Cc:Subject:Date:From; b=OYqbEABqXL3pu8l3C4NcNP8y7KKU+tyfy2ue/h7/0blS0uj+NweZbTl6HjEuCJ/Fg qsqiyj6m+04joMzBm/ReK2L1L3bn80dPO4xHQb2GU51Ue/rxJ4nuVK15fQhq91BXy2 DMG2RCI1tzMKx1ouFab2x8L+aGerCeIwuiTcf+RA= 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> X-Mailer: git-send-email 2.17.1 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 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