From nobody Mon Feb 9 06:28:58 2026 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 B93DE1FD114; Sun, 24 Mar 2024 23:02:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711321329; cv=none; b=pT7mARhiJV0Kw+50SR5UYOpwY0XnWoE9KF6eEdAnWcMlM+WaE/awW0pQmMr65QU8BEYh4JvaiKAWid2tg2KT1B62l7wo/YJ7sLlPJ37lquC074S2Pcv4kWMSmALiYhylzVCUseL9CELBeYsXNF7hXbIz24k3KOQtcLx6YUw9oCo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711321329; c=relaxed/simple; bh=rd9CTn5d36v+u366AsJVE1eQgwQIsnkSjg/Q6MfoA3Y=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=AvQvUpICJWf8l9uu09+BKYkWtlIHXs6rUGm0WR3JzMibRkb050y+g+jR9srd/xDsQwKvifeJ9FvhX6yKCFfBcjG9e+1uPnInyrGMXhHUfB9VLuk/4GRDSygnGaHCRdQgYsgOhI9sEkw5gfmQTlynHZp0+op+dL2AjVMBiM9TVQQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NHOBafGx; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="NHOBafGx" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F41BAC433C7; Sun, 24 Mar 2024 23:02:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711321329; bh=rd9CTn5d36v+u366AsJVE1eQgwQIsnkSjg/Q6MfoA3Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NHOBafGxoE1Gieh1NTYOr6CIJu0suovL3o0t8kE2GkDR7OkVYt/4bJMemYyIdqpx4 IIoO48zPA5BBYHtbjwotTkl5AfeYgLnLR6+4fvU3kcjccggxI3QhgO43LU2l7jk0OW UWDe1gHmwBZw4ivWQ7tlsdBtjnwmCc39dKnoaGKwfNLTi93xkj7dD6d3a9KOENYJta ecO6EnQpZ7XoPqjGUukglZ3sWCxVjj7FVd1NZVAbQoueqQLlfseSnk7TpHiN+RwEFU hNz/5TQQ4JTyoyFppQnroB+LXbXBQT685mfQESzrWiGESkJQdNyKHlSPa/DTryivub RhaMN6I0DoBhA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Yuxuan Hu <20373622@buaa.edu.cn>, Luiz Augusto von Dentz , Sasha Levin Subject: [PATCH 6.6 053/638] Bluetooth: rfcomm: Fix null-ptr-deref in rfcomm_check_security Date: Sun, 24 Mar 2024 18:51:30 -0400 Message-ID: <20240324230116.1348576-54-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240324230116.1348576-1-sashal@kernel.org> References: <20240324230116.1348576-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Yuxuan Hu <20373622@buaa.edu.cn> [ Upstream commit 2535b848fa0f42ddff3e5255cf5e742c9b77bb26 ] During our fuzz testing of the connection and disconnection process at the RFCOMM layer, we discovered this bug. By comparing the packets from a normal connection and disconnection process with the testcase that triggered a KASAN report. We analyzed the cause of this bug as follows: 1. In the packets captured during a normal connection, the host sends a `Read Encryption Key Size` type of `HCI_CMD` packet (Command Opcode: 0x1408) to the controller to inquire the length of encryption key.After receiving this packet, the controller immediately replies with a Command Completepacket (Event Code: 0x0e) to return the Encryption Key Size. 2. In our fuzz test case, the timing of the controller's response to this packet was delayed to an unexpected point: after the RFCOMM and L2CAP layers had disconnected but before the HCI layer had disconnected. 3. After receiving the Encryption Key Size Response at the time described in point 2, the host still called the rfcomm_check_security function. However, by this time `struct l2cap_conn *conn =3D l2cap_pi(sk)->chan->conn= ;` had already been released, and when the function executed `return hci_conn_security(conn->hcon, d->sec_level, auth_type, d->out);`, specifically when accessing `conn->hcon`, a null-ptr-deref error occurred. To fix this bug, check if `sk->sk_state` is BT_CLOSED before calling rfcomm_recv_frame in rfcomm_process_rx. Signed-off-by: Yuxuan Hu <20373622@buaa.edu.cn> Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin --- net/bluetooth/rfcomm/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/bluetooth/rfcomm/core.c b/net/bluetooth/rfcomm/core.c index 053ef8f25fae4..1d34d84970332 100644 --- a/net/bluetooth/rfcomm/core.c +++ b/net/bluetooth/rfcomm/core.c @@ -1941,7 +1941,7 @@ static struct rfcomm_session *rfcomm_process_rx(struc= t rfcomm_session *s) /* Get data directly from socket receive queue without copying it. */ while ((skb =3D skb_dequeue(&sk->sk_receive_queue))) { skb_orphan(skb); - if (!skb_linearize(skb)) { + if (!skb_linearize(skb) && sk->sk_state !=3D BT_CLOSED) { s =3D rfcomm_recv_frame(s, skb); if (!s) break; --=20 2.43.0