From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9A1012566 for ; Tue, 18 Apr 2023 12:29:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1C8D3C433D2; Tue, 18 Apr 2023 12:29:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1681820990; bh=CFWr4sOYekLyCsW0rH5z7p3rv566oaCQVXu/dNcEckY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wUQ+lBQCzxc3VIyB3l+0QgbjKhSZVE43YhgpJeMJKkcyUkH77iyfOSLnvzfl3OHeC mBPYR/ZTLZmze7lRsTFFJUgNc8VhYGe6bUPBLC8Sx26nIqq7AFnT4q3UxylU4YdRFY j6+BNL98UmUYdqT7SZ/BeDqlJLSLNkST/YJVGcuU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, stable@kernel.org, Luiz Augusto von Dentz , Min Li Subject: [PATCH 5.4 50/92] Bluetooth: L2CAP: Fix use-after-free in l2cap_disconnect_{req,rsp} Date: Tue, 18 Apr 2023 14:21:25 +0200 Message-Id: <20230418120306.603860332@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230418120304.658273364@linuxfoundation.org> References: <20230418120304.658273364@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Luiz Augusto von Dentz commit a2a9339e1c9deb7e1e079e12e27a0265aea8421a upstream. Similar to commit d0be8347c623 ("Bluetooth: L2CAP: Fix use-after-free caused by l2cap_chan_put"), just use l2cap_chan_hold_unless_zero to prevent referencing a channel that is about to be destroyed. Cc: stable@kernel.org Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Min Li Signed-off-by: Greg Kroah-Hartman --- net/bluetooth/l2cap_core.c | 24 ++++++------------------ 1 file changed, 6 insertions(+), 18 deletions(-) --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -4368,33 +4368,27 @@ static inline int l2cap_disconnect_req(s BT_DBG("scid 0x%4.4x dcid 0x%4.4x", scid, dcid); - mutex_lock(&conn->chan_lock); - - chan = __l2cap_get_chan_by_scid(conn, dcid); + chan = l2cap_get_chan_by_scid(conn, dcid); if (!chan) { - mutex_unlock(&conn->chan_lock); cmd_reject_invalid_cid(conn, cmd->ident, dcid, scid); return 0; } - l2cap_chan_hold(chan); - l2cap_chan_lock(chan); - rsp.dcid = cpu_to_le16(chan->scid); rsp.scid = cpu_to_le16(chan->dcid); l2cap_send_cmd(conn, cmd->ident, L2CAP_DISCONN_RSP, sizeof(rsp), &rsp); chan->ops->set_shutdown(chan); + mutex_lock(&conn->chan_lock); l2cap_chan_del(chan, ECONNRESET); + mutex_unlock(&conn->chan_lock); chan->ops->close(chan); l2cap_chan_unlock(chan); l2cap_chan_put(chan); - mutex_unlock(&conn->chan_lock); - return 0; } @@ -4414,33 +4408,27 @@ static inline int l2cap_disconnect_rsp(s BT_DBG("dcid 0x%4.4x scid 0x%4.4x", dcid, scid); - mutex_lock(&conn->chan_lock); - - chan = __l2cap_get_chan_by_scid(conn, scid); + chan = l2cap_get_chan_by_scid(conn, scid); if (!chan) { mutex_unlock(&conn->chan_lock); return 0; } - l2cap_chan_hold(chan); - l2cap_chan_lock(chan); - if (chan->state != BT_DISCONN) { l2cap_chan_unlock(chan); l2cap_chan_put(chan); - mutex_unlock(&conn->chan_lock); return 0; } + mutex_lock(&conn->chan_lock); l2cap_chan_del(chan, 0); + mutex_unlock(&conn->chan_lock); chan->ops->close(chan); l2cap_chan_unlock(chan); l2cap_chan_put(chan); - mutex_unlock(&conn->chan_lock); - return 0; }