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=-13.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,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 4EAEFC4727C for ; Tue, 29 Sep 2020 12:11:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D611A20759 for ; Tue, 29 Sep 2020 12:11:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601381513; bh=KYttkS2Umz7dHsgslJdO4PLnHstjNvLIcBm6I8m1c2Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=dGkrrTomMtGHLaxFDxfoxrkU4M/qVibycTn34C+Bf0Y7HJmGIYuYy4nGebOJ24RYt JKQF97G2nNEF1I5QZK76AZxuyUAumqMil24oipg0u0FYsK7NhFcU8pGuugunrBF0jL lcwPKVSqq3Wk4cXev62rXMqacj0G8deCjj2E3giI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731989AbgI2MLw (ORCPT ); Tue, 29 Sep 2020 08:11:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:58098 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730161AbgI2Lhd (ORCPT ); Tue, 29 Sep 2020 07:37:33 -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 06A5723BCA; Tue, 29 Sep 2020 11:35:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601379316; bh=KYttkS2Umz7dHsgslJdO4PLnHstjNvLIcBm6I8m1c2Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DtxOy4G/97I8GOK4XBFNMmIUNtMp0qVwCQVhtdazz2GjKLtljRJhFo7UkVA2aGU4y TBsDxcnwkMa24A0oJTDiK08gqdmupO/VdaOeC5VLbl2rMgbIu3y18Vlh/0w4EMjfVK opnFuSDTbWlQtAfNuhpxSYasOUmNoZROqcDLQeNU= 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 5.4 108/388] Bluetooth: prefetch channel before killing sock Date: Tue, 29 Sep 2020 12:57:19 +0200 Message-Id: <20200929110015.705368150@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200929110010.467764689@linuxfoundation.org> References: <20200929110010.467764689@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 ab65304f3f637..390a9afab6473 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -1193,6 +1193,7 @@ 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); @@ -1202,15 +1203,16 @@ 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