From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-3704313-1519414730-2-5132349427969292177 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.001, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='CN', FromHeader='org', MailFrom='org' X-Spam-charsets: plain='UTF-8' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1519414730; b=uhtHIykD15TH2QhXxzTPNRyKjGWZgNhyuTcUUmuTfBKBSDo JaAp8Z+F2nCErE7VTBfwElUBQJrCrK7VDOcHVgCgC45Cq6C+1BlOVgZd7OQangt9 pENi4wN1HRjiWXCqiLLkg3uGuHDwhAob6HXRYCeDS1jg7HuS0w3Vifp3gk2rOvE0 wcpUzpKMN2xCxruXx6wFh6qTvg3LP73BTFkicxd2L25hLv9URZByMZN4padKrgUe UcsSJ30QDkjKb/yu+WgzkQKMgdlLNsYTUBVapIKbb6rYXCsq//ZMj1Dc+5sRz037 WZNJn64RqHgMTFYonvAF/7xKXms8dAwtm+CgAwQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-type:sender :list-id; s=arctest; t=1519414730; bh=VuR6tsAyx+jq211cOfpDOM8aGr TaNn6Sw1tFqiUyDFQ=; b=mGxxzJ7Ypix8nXcBCuyTUQkTapTY2Df5y1dShG6jrj Dmx79DV1LfFL9RaSPjdhyFW8S2QXCIhG7oOV+rdTihFs5LkDD0FGNSjWZPV7fSme 3+3L0oMyCx52qcQbpxTeb+0ctK2Z/B2VHIhtD1yCJEY6qsjf1HJ/V28PGjJel7Yi GV2S23/9HB1DxK9leq8KhqkrF2DQZbScahjdMoSeF6G7HG8XyQ1IY8BeVOrcoH2t jSnx6JGw40qjeMh8mgxZPALBcKGxjVhLZz8g5IfjecxVvbJmvHtJ+hADTQchlMry izIRLdQHWD6v4kT/nZDCI0z/SQ4cqyRPPzIvIzn9i1Xw== ARC-Authentication-Results: i=1; mx6.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes Authentication-Results: mx6.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934322AbeBWSt5 (ORCPT ); Fri, 23 Feb 2018 13:49:57 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:45450 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934602AbeBWStw (ORCPT ); Fri, 23 Feb 2018 13:49:52 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+dbb7c1161485e61b0241@syzkaller.appspotmail.com, Jason Wang , "Michael S. Tsirkin" , "David S. Miller" Subject: [PATCH 4.14 002/159] vhost: use mutex_lock_nested() in vhost_dev_lock_vqs() Date: Fri, 23 Feb 2018 19:25:10 +0100 Message-Id: <20180223170743.355506815@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180223170743.086611315@linuxfoundation.org> References: <20180223170743.086611315@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jason Wang commit e9cb4239134c860e5f92c75bf5321bd377bb505b upstream. We used to call mutex_lock() in vhost_dev_lock_vqs() which tries to hold mutexes of all virtqueues. This may confuse lockdep to report a possible deadlock because of trying to hold locks belong to same class. Switch to use mutex_lock_nested() to avoid false positive. Fixes: 6b1e6cc7855b0 ("vhost: new device IOTLB API") Reported-by: syzbot+dbb7c1161485e61b0241@syzkaller.appspotmail.com Signed-off-by: Jason Wang Acked-by: Michael S. Tsirkin Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/vhost/vhost.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -904,7 +904,7 @@ static void vhost_dev_lock_vqs(struct vh { int i = 0; for (i = 0; i < d->nvqs; ++i) - mutex_lock(&d->vqs[i]->mutex); + mutex_lock_nested(&d->vqs[i]->mutex, i); } static void vhost_dev_unlock_vqs(struct vhost_dev *d)