From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx49T4MDqz1yLdNE8EIHM9dKIa7HvliddLjGs1TGRDmriE49bxf5BIO8eKwATlT5vnf0vtxs0 ARC-Seal: i=1; a=rsa-sha256; t=1523399599; cv=none; d=google.com; s=arc-20160816; b=nAq0sZRngrh2o243TusrA9va0+3Oxl3OeoxDeGQrdK/5HLQ4ZQyZeZcUgvkCvdh3sH 6OMHnGzsMqSRibRYz5oqD3Q0IEF3khsGTnMcUmhSEB9FGjJXpQalP/TP8T4STYYnNVoU MzlSLwUecjaJJ18nl9KEQv+SCI8JlyqoeJNpauzLbfZxC+cFROOxlL29PY7s8tXU0W8e VPTt26oSC8C2cQ6JtsnB7MdvgUL+wlKakWE+GWB3aXyc+pzCrvmBpUsH2tz2CRPpDJx8 VaJkN2zljapn+SEqcFaYVGGebXANs0W/b416ISkJtbLtdvVqiIkHaQ/UA+ljkz8yZXGR D35w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=miemeAe90eYprWlSnrPcNS+6l0Mbw9B7+xLYcMxR56E=; b=rvBh7R88uUyy2vFNhlpsLBPIVN6DDTYLQpB9WWo7Xv1rhpeHvhd+4PbIVUygtgZnOY JWtxTWEF7j8p26xcQt3zhfKcPPkypeDHZK4ehQoLu9UZkYTOwtY3hi7tRkcuk2cOsjMG +o+Fpcxx3FMoYUZ29rN9Wef/wM4sD3xoQHtLhls3fGGEKFu6XMdibDb4RhiSXsRxEqut s2UlPi65OOquDZy2sMFa2Zl9k3XTbO5rbIhJq9RtgS29w0ExsEpl+6EAFNU9iLIbmy0u NY4QDSZhIsrC1I9gTqQhx7Eb9jkJsMdubKMigv8Kb5IJTITOy1FMOF47qUcIDtnDLdjq 1Rew== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+7f073540b1384a614e09@syzkaller.appspotmail.com, Jason Wang , "Michael S. Tsirkin" , "David S. Miller" Subject: [PATCH 4.15 167/168] vhost_net: add missing lock nesting notation Date: Wed, 11 Apr 2018 00:25:09 +0200 Message-Id: <20180410212808.329783793@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180410212800.144079021@linuxfoundation.org> References: <20180410212800.144079021@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1597400258502642813?= X-GMAIL-MSGID: =?utf-8?q?1597400258502642813?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jason Wang [ Upstream commit aaa3149bbee9ba9b4e6f0bd6e3e7d191edeae942 ] We try to hold TX virtqueue mutex in vhost_net_rx_peek_head_len() after RX virtqueue mutex is held in handle_rx(). This requires an appropriate lock nesting notation to calm down deadlock detector. Fixes: 0308813724606 ("vhost_net: basic polling support") Reported-by: syzbot+7f073540b1384a614e09@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/net.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -618,7 +618,7 @@ static int vhost_net_rx_peek_head_len(st if (!len && vq->busyloop_timeout) { /* Both tx vq and rx socket were polled here */ - mutex_lock(&vq->mutex); + mutex_lock_nested(&vq->mutex, 1); vhost_disable_notify(&net->dev, vq); preempt_disable(); @@ -751,7 +751,7 @@ static void handle_rx(struct vhost_net * struct iov_iter fixup; __virtio16 num_buffers; - mutex_lock(&vq->mutex); + mutex_lock_nested(&vq->mutex, 0); sock = vq->private_data; if (!sock) goto out;