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 4955EC64EC4 for ; Fri, 10 Mar 2023 14:31:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232477AbjCJObP (ORCPT ); Fri, 10 Mar 2023 09:31:15 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52812 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232513AbjCJOaz (ORCPT ); Fri, 10 Mar 2023 09:30:55 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 19A8111EEBF for ; Fri, 10 Mar 2023 06:29:51 -0800 (PST) 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 6CD0B6191D for ; Fri, 10 Mar 2023 14:29:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5917FC433EF; Fri, 10 Mar 2023 14:29:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678458589; bh=usRFb5QlJ1+hnIuhu1PlTrwLSqVq6DxC7XY2IemhzMk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Y1lQVOAIcRLxw01on/ATKKW+++TOAQe87DSN8k9R4H7kCDmj4Bq3iWshoA2EfVtap IlocGPheQTgM5zCHm4ZnreRwetdt/2GWnmJHGO6haWYXhn2cJkKYdpPdKfYYz9mVr4 jUYOkGzxBzxUnX7V2gv5rJydcj48puskS3CRpNuI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Alexander Coffin , Luiz Augusto von Dentz , Sasha Levin Subject: [PATCH 5.4 077/357] Bluetooth: L2CAP: Fix potential user-after-free Date: Fri, 10 Mar 2023 14:36:06 +0100 Message-Id: <20230310133737.392589272@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230310133733.973883071@linuxfoundation.org> References: <20230310133733.973883071@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: stable@vger.kernel.org From: Luiz Augusto von Dentz [ Upstream commit df5703348813235874d851934e957c3723d71644 ] This fixes all instances of which requires to allocate a buffer calling alloc_skb which may release the chan lock and reacquire later which makes it possible that the chan is disconnected in the meantime. Fixes: a6a5568c03c4 ("Bluetooth: Lock the L2CAP channel when sending") Reported-by: Alexander Coffin Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin --- net/bluetooth/l2cap_core.c | 24 ------------------------ net/bluetooth/l2cap_sock.c | 8 ++++++++ 2 files changed, 8 insertions(+), 24 deletions(-) diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index 0e51ed3412ef3..4f286c76a50d4 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -2526,14 +2526,6 @@ int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len) if (IS_ERR(skb)) return PTR_ERR(skb); - /* Channel lock is released before requesting new skb and then - * reacquired thus we need to recheck channel state. - */ - if (chan->state != BT_CONNECTED) { - kfree_skb(skb); - return -ENOTCONN; - } - l2cap_do_send(chan, skb); return len; } @@ -2577,14 +2569,6 @@ int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len) if (IS_ERR(skb)) return PTR_ERR(skb); - /* Channel lock is released before requesting new skb and then - * reacquired thus we need to recheck channel state. - */ - if (chan->state != BT_CONNECTED) { - kfree_skb(skb); - return -ENOTCONN; - } - l2cap_do_send(chan, skb); err = len; break; @@ -2605,14 +2589,6 @@ int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len) */ err = l2cap_segment_sdu(chan, &seg_queue, msg, len); - /* The channel could have been closed while segmenting, - * check that it is still connected. - */ - if (chan->state != BT_CONNECTED) { - __skb_queue_purge(&seg_queue); - err = -ENOTCONN; - } - if (err) break; diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c index 08e9f332adad3..0fa5ced767a24 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -1433,6 +1433,14 @@ static struct sk_buff *l2cap_sock_alloc_skb_cb(struct l2cap_chan *chan, if (!skb) return ERR_PTR(err); + /* Channel lock is released before requesting new skb and then + * reacquired thus we need to recheck channel state. + */ + if (chan->state != BT_CONNECTED) { + kfree_skb(skb); + return ERR_PTR(-ENOTCONN); + } + skb->priority = sk->sk_priority; bt_cb(skb)->l2cap.chan = chan; -- 2.39.2