Return-Path: From: Nick Pelly To: linux-bluetooth@vger.kernel.org Cc: Nick Pelly Subject: [PATCH] Bluetooth: Do not call rfcomm_session_put() due to RFCOMM UA on closed socket. Date: Wed, 3 Feb 2010 16:18:36 -0800 Message-Id: <1265242716-68978-1-git-send-email-npelly@google.com> Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Processing a RFCOMM UA frame when the socket is closed and we were not the RFCOMM initiator would cause rfcomm_session_put() to be called twice during rfcomm_process_rx(). This would cause a kernel panic in rfcomm_session_close. This could be easily reproduced during disconnect with devices such as Motorola H270 that send RFCOMM UA followed quickly by L2CAP disconnect request. This hcidump for this looks like: 2009-09-21 17:22:37.788895 < ACL data: handle 1 flags 0x02 dlen 8 L2CAP(d): cid 0x0041 len 4 [psm 3] RFCOMM(s): DISC: cr 0 dlci 20 pf 1 ilen 0 fcs 0x7d 2009-09-21 17:22:37.906204 > HCI Event: Number of Completed Packets (0x13) plen 5 handle 1 packets 1 2009-09-21 17:22:37.933090 > ACL data: handle 1 flags 0x02 dlen 8 L2CAP(d): cid 0x0040 len 4 [psm 3] RFCOMM(s): UA: cr 0 dlci 20 pf 1 ilen 0 fcs 0x57 2009-09-21 17:22:38.636764 < ACL data: handle 1 flags 0x02 dlen 8 L2CAP(d): cid 0x0041 len 4 [psm 3] RFCOMM(s): DISC: cr 0 dlci 0 pf 1 ilen 0 fcs 0x9c 2009-09-21 17:22:38.744125 > HCI Event: Number of Completed Packets (0x13) plen 5 handle 1 packets 1 2009-09-21 17:22:38.763687 > ACL data: handle 1 flags 0x02 dlen 8 L2CAP(d): cid 0x0040 len 4 [psm 3] RFCOMM(s): UA: cr 0 dlci 0 pf 1 ilen 0 fcs 0xb6 2009-09-21 17:22:38.783554 > ACL data: handle 1 flags 0x02 dlen 12 L2CAP(s): Disconn req: dcid 0x0040 scid 0x0041 Avoid calling rfcomm_session_put() twice by skipping this call in rfcomm_recv_ua() if the socket is closed. Signed-off-by: Nick Pelly --- net/bluetooth/rfcomm/core.c | 6 +++++- 1 files changed, 5 insertions(+), 1 deletions(-) diff --git a/net/bluetooth/rfcomm/core.c b/net/bluetooth/rfcomm/core.c index 25692bc..950d95c 100644 --- a/net/bluetooth/rfcomm/core.c +++ b/net/bluetooth/rfcomm/core.c @@ -1148,7 +1148,11 @@ static int rfcomm_recv_ua(struct rfcomm_session *s, u8 dlci) break; case BT_DISCONN: - rfcomm_session_put(s); + /* When socket is closed and we are not RFCOMM + * initiator rfcomm_process_rx already calls + * rfcomm_session_put() */ + if (s->sock->sk->sk_state != BT_CLOSED) + rfcomm_session_put(s); break; } } -- 1.6.5.3