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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A72C3C433FE for ; Wed, 19 Oct 2022 09:28:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233657AbiJSJ2u (ORCPT ); Wed, 19 Oct 2022 05:28:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45338 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233508AbiJSJ1O (ORCPT ); Wed, 19 Oct 2022 05:27:14 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 01123C6962; Wed, 19 Oct 2022 02:12:10 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 1595661840; Wed, 19 Oct 2022 09:10:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 257BBC43470; Wed, 19 Oct 2022 09:10:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1666170616; bh=a00U9GHBoFljlewPFnHrOgja+rsegUW3jaFRMRIvNCM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JKIPBJO5kw5sqCwxmSEI6JNuDXVkKgyiJfjHlwFJn48remV6h3E+rlHDEFvg8rG4M uKunx1n+FlzRXfEISBd4j2rehRM4Dtmcc+/4FSx0P11V46F4pU+KuHZLLjZjEW7dH2 q+vOFjd2e57KmEJeV5GXi2HbnsDSTuvBRYrzrO2s= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Luiz Augusto von Dentz , Sungwoo Kim , Sasha Levin Subject: [PATCH 6.0 723/862] Bluetooth: L2CAP: Fix user-after-free Date: Wed, 19 Oct 2022 10:33:30 +0200 Message-Id: <20221019083321.870305290@linuxfoundation.org> X-Mailer: git-send-email 2.38.0 In-Reply-To: <20221019083249.951566199@linuxfoundation.org> References: <20221019083249.951566199@linuxfoundation.org> User-Agent: quilt/0.67 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: Luiz Augusto von Dentz [ Upstream commit 35fcbc4243aad7e7d020b7c1dfb14bb888b20a4f ] This uses l2cap_chan_hold_unless_zero() after calling __l2cap_get_chan_blah() to prevent the following trace: Bluetooth: l2cap_core.c:static void l2cap_chan_destroy(struct kref *kref) Bluetooth: chan 0000000023c4974d Bluetooth: parent 00000000ae861c08 ================================================================== BUG: KASAN: use-after-free in __mutex_waiter_is_first kernel/locking/mutex.c:191 [inline] BUG: KASAN: use-after-free in __mutex_lock_common kernel/locking/mutex.c:671 [inline] BUG: KASAN: use-after-free in __mutex_lock+0x278/0x400 kernel/locking/mutex.c:729 Read of size 8 at addr ffff888006a49b08 by task kworker/u3:2/389 Link: https://lore.kernel.org/lkml/20220622082716.478486-1-lee.jones@linaro.org Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sungwoo Kim Signed-off-by: Sasha Levin --- net/bluetooth/l2cap_core.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index 770891f68703..1f34b82ca0ec 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -4309,6 +4309,12 @@ static int l2cap_connect_create_rsp(struct l2cap_conn *conn, } } + chan = l2cap_chan_hold_unless_zero(chan); + if (!chan) { + err = -EBADSLT; + goto unlock; + } + err = 0; l2cap_chan_lock(chan); @@ -4338,6 +4344,7 @@ static int l2cap_connect_create_rsp(struct l2cap_conn *conn, } l2cap_chan_unlock(chan); + l2cap_chan_put(chan); unlock: mutex_unlock(&conn->chan_lock); -- 2.35.1