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 E9294C25B08 for ; Mon, 15 Aug 2022 20:02:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232917AbiHOUCR (ORCPT ); Mon, 15 Aug 2022 16:02:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55862 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345945AbiHOUBF (ORCPT ); Mon, 15 Aug 2022 16:01:05 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D008A7B7BA; Mon, 15 Aug 2022 11:53:42 -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 ams.source.kernel.org (Postfix) with ESMTPS id 1A924B810A2; Mon, 15 Aug 2022 18:53:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 66D49C433C1; Mon, 15 Aug 2022 18:53:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660589616; bh=ypcTEHAAN56lMkwcSW2kJ2Sjqa0FjUipNQmNtZq0vRg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Vu4BZZgAMZeyDKNUDDpYHvxGRlDoO8AXwvxq4wzjgYuMbmPGxHdLlWphziANjqWMc v0gm4a6FIeJ2RoDtqUZCls6sAV4fPZsbykLyc3l/Cs+6uhW3Ps8qjNWsWpn9mNZDUH RSvKu887ROlAse51yr9XTufGb0i5ANvAG7ZMYds4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , Luiz Augusto von Dentz Subject: [PATCH 5.15 775/779] Bluetooth: L2CAP: Fix l2cap_global_chan_by_psm regression Date: Mon, 15 Aug 2022 20:06:59 +0200 Message-Id: <20220815180410.517422014@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220815180337.130757997@linuxfoundation.org> References: <20220815180337.130757997@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 commit 332f1795ca202489c665a75e62e18ff6284de077 upstream. The patch d0be8347c623: "Bluetooth: L2CAP: Fix use-after-free caused by l2cap_chan_put" from Jul 21, 2022, leads to the following Smatch static checker warning: net/bluetooth/l2cap_core.c:1977 l2cap_global_chan_by_psm() error: we previously assumed 'c' could be null (see line 1996) Fixes: d0be8347c623 ("Bluetooth: L2CAP: Fix use-after-free caused by l2cap_chan_put") Reported-by: Dan Carpenter Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman --- net/bluetooth/l2cap_core.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -1970,11 +1970,11 @@ static struct l2cap_chan *l2cap_global_c bdaddr_t *dst, u8 link_type) { - struct l2cap_chan *c, *c1 = NULL; + struct l2cap_chan *c, *tmp, *c1 = NULL; read_lock(&chan_list_lock); - list_for_each_entry(c, &chan_list, global_l) { + list_for_each_entry_safe(c, tmp, &chan_list, global_l) { if (state && c->state != state) continue; @@ -1993,11 +1993,10 @@ static struct l2cap_chan *l2cap_global_c dst_match = !bacmp(&c->dst, dst); if (src_match && dst_match) { c = l2cap_chan_hold_unless_zero(c); - if (!c) - continue; - - read_unlock(&chan_list_lock); - return c; + if (c) { + read_unlock(&chan_list_lock); + return c; + } } /* Closest match */