Received: by 2002:a05:6a10:22f:0:0:0:0 with SMTP id 15csp3700623pxk; Tue, 29 Sep 2020 04:11:16 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwq98fW1F5Ja1lI/hbI8vH3pYh6OSB6LUJQwweVsk/0QQLqlKZ/t9V51N1A7TwIwFFl/PjY X-Received: by 2002:a17:906:5f8a:: with SMTP id a10mr3161626eju.502.1601377876105; Tue, 29 Sep 2020 04:11:16 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1601377876; cv=none; d=google.com; s=arc-20160816; b=T4sGxqoqCjQNBfpgQPQ3a8anehua3FfxuXkvEhY2Pm0S1TLGeGFJSBeSQ3H/trNS8d 49IZIfyz3Lv9dKsmHqxl5ibTGcwC8z3tmnLsW31e9OpYpACQz0nGoH11ZTI/1drsyyK0 sO9KeIKkTLT/as1CWqNb0cP2SCNgV37LVTaGkbZi+dPcyxMm1bDeNWZAN18FVl/hQYx7 on+PwZtdp1Rb1C4mDPdmQX0kqcipPjCXVFa/4K/TE6AsrvIv9nwdnNmkxL3NdMJUu3dP D9gsfxvSK3XkarPxITymP1OkCC0eEziiPtDP/8/M0sQp7HTade0/abYEWUg71jkbKBio JVPg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :user-agent:references:in-reply-to:message-id:date:subject:cc:to :from:dkim-signature; bh=KRuCgv8+St4C3t55aS0QcjRBhSPt4Gf/tr6A0clqQO8=; b=fK5MpAHDVRxaEQXf1Y/Jdkc+qZLB8yiWNdbgRdVSDQUVH4D1FZJdjKDfnAJVeon4UL u7mu5pfthQwpFsH5X7D7E+qRtHZlXRWNz6yiY4x7ifrLFvbz2CqhrXHmZULAp0fiBFvo ou9FipKRj53qCAOGSpHDUyMX6vUVR3LsXnJVEzrd4SD/hxbvg0BVwqRn94ClttKZzoVJ FljowdwP8sgZDhz3rLyET4tUkaclIN40JfIoeU57ZaUAQGKJ4uEOlDMUrorr9l01lRjR IAGEbFALVnYHwAqVdO/3p57brJNM2Yx6f9lyBx7OsHy3/f7Y3eGxaep8EyR5vaJKln4+ dX0g== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=mngGFJIa; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=linuxfoundation.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id w4si2616644ede.468.2020.09.29.04.10.53; Tue, 29 Sep 2020 04:11:16 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=mngGFJIa; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=linuxfoundation.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728848AbgI2LGn (ORCPT + 99 others); Tue, 29 Sep 2020 07:06:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:41532 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728126AbgI2LFL (ORCPT ); Tue, 29 Sep 2020 07:05:11 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 08ED620C09; Tue, 29 Sep 2020 11:05:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601377510; bh=SQaBKSkiYQ6kVs5Ju1rSEjGVPCqXz8ymsFbpTrxbToQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mngGFJIa2LUAIIqBeZPMqxl83VQZwCUzxGLujqn66mSHwWLO+xYcOzh5UpRUqFXT2 WtOI5Iozsnzf3mqGbnK9QpxvwzRYV1iziR7VBF+3fg8FW0yyxJbiqnf+LKrBbnwrFZ ANNxmDLNkMC+Hjis8ay2CWE+K54upuFvY+nGR6ak= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+c3c5bdea7863886115dc@syzkaller.appspotmail.com, Manish Mandlik , Hillf Danton , Marcel Holtmann , Sasha Levin Subject: [PATCH 4.4 31/85] Bluetooth: prefetch channel before killing sock Date: Tue, 29 Sep 2020 12:59:58 +0200 Message-Id: <20200929105929.781820236@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200929105928.198942536@linuxfoundation.org> References: <20200929105928.198942536@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Hillf Danton [ Upstream commit 2a154903cec20fb64ff4d7d617ca53c16f8fd53a ] Prefetch channel before killing sock in order to fix UAF like BUG: KASAN: use-after-free in l2cap_sock_release+0x24c/0x290 net/bluetooth/l2cap_sock.c:1212 Read of size 8 at addr ffff8880944904a0 by task syz-fuzzer/9751 Reported-by: syzbot+c3c5bdea7863886115dc@syzkaller.appspotmail.com Fixes: 6c08fc896b60 ("Bluetooth: Fix refcount use-after-free issue") Cc: Manish Mandlik Signed-off-by: Hillf Danton Signed-off-by: Marcel Holtmann Signed-off-by: Sasha Levin --- net/bluetooth/l2cap_sock.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c index cb024c25530a3..e562385d9440e 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -1189,6 +1189,7 @@ static int l2cap_sock_release(struct socket *sock) { struct sock *sk = sock->sk; int err; + struct l2cap_chan *chan; BT_DBG("sock %p, sk %p", sock, sk); @@ -1198,15 +1199,16 @@ static int l2cap_sock_release(struct socket *sock) bt_sock_unlink(&l2cap_sk_list, sk); err = l2cap_sock_shutdown(sock, 2); + chan = l2cap_pi(sk)->chan; - l2cap_chan_hold(l2cap_pi(sk)->chan); - l2cap_chan_lock(l2cap_pi(sk)->chan); + l2cap_chan_hold(chan); + l2cap_chan_lock(chan); sock_orphan(sk); l2cap_sock_kill(sk); - l2cap_chan_unlock(l2cap_pi(sk)->chan); - l2cap_chan_put(l2cap_pi(sk)->chan); + l2cap_chan_unlock(chan); + l2cap_chan_put(chan); return err; } -- 2.25.1