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 A84FAC32772 for ; Tue, 23 Aug 2022 08:28:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243491AbiHWI1w (ORCPT ); Tue, 23 Aug 2022 04:27:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34120 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243222AbiHWIXx (ORCPT ); Tue, 23 Aug 2022 04:23:53 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B3D602716; Tue, 23 Aug 2022 01:13:20 -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 1087AB81C3D; Tue, 23 Aug 2022 08:12:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7AEEDC433C1; Tue, 23 Aug 2022 08:12:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661242372; bh=t9EAyhTB6WaOrs6vp1R5UqNAeAWhZro/XkIxBgAHZao=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GM8m7WY0eBOAlOG5rnFv1r/zlR2EWfR4XyXsJkX2L9HaOfNTZXLlYMb0QtPGFsqds WwC2ahRSSPFV651EfBOCju6/mBD0zBu6NIijCTgAMPk6q5nSrIPaFi3jwbPRrQJHSR fdwKUzZjxJFTdo7f4hzUcH90SYpDGIWiz1NaLvnM= 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 4.9 062/101] Bluetooth: L2CAP: Fix l2cap_global_chan_by_psm regression Date: Tue, 23 Aug 2022 10:03:35 +0200 Message-Id: <20220823080036.947499547@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220823080034.579196046@linuxfoundation.org> References: <20220823080034.579196046@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 @@ -1804,11 +1804,11 @@ 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; @@ -1827,11 +1827,10 @@ 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 */