From 31e8ce80baa7eaed9eec611deba982b24beed9e5 Mon Sep 17 00:00:00 2001 From: Seung-Woo Kim Date: Tue, 5 Nov 2013 18:46:33 +0900 Subject: [PATCH] Bluetooth: Fix crash in l2cap_chan_send after l2cap_chan_del Removing a bond and disconnecting from a specific remote device can cause l2cap_chan_send() is called after l2cap_chan_del() is called. This causes following crash. [ 1384.972086] Unable to handle kernel NULL pointer dereference at virtual address 00000008 [ 1384.972090] pgd = c0004000 [ 1384.972125] [00000008] *pgd=00000000 [ 1384.972137] Internal error: Oops: 17 [#1] PREEMPT SMP ARM [ 1384.972144] Modules linked in: [ 1384.972156] CPU: 0 PID: 841 Comm: krfcommd Not tainted 3.10.14-gdf22a71-dirty #435 [ 1384.972162] task: df29a100 ti: df178000 task.ti: df178000 [ 1384.972182] PC is at l2cap_create_basic_pdu+0x30/0x1ac [ 1384.972191] LR is at l2cap_chan_send+0x100/0x1d4 [ 1384.972198] pc : [] lr : [] psr: 40000113 [ 1384.972198] sp : df179d40 ip : c083a010 fp : 00000008 [ 1384.972202] r10: 00000004 r9 : 0000065a r8 : 000003f5 [ 1384.972206] r7 : 00000000 r6 : 00000000 r5 : df179e84 r4 : da557000 [ 1384.972210] r3 : 00000000 r2 : 00000004 r1 : df179e84 r0 : 00000000 [ 1384.972215] Flags: nZcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel [ 1384.972220] Control: 10c53c7d Table: 5c8b004a DAC: 00000015 [ 1384.972224] Process krfcommd (pid: 841, stack limit = 0xdf178238) [ 1384.972229] Stack: (0xdf179d40 to 0xdf17a000) [ 1384.972238] 9d40: 00000000 da557000 00000004 df179e84 00000004 000003f5 0000065a 00000000 [ 1384.972245] 9d60: 00000008 c0521c78 df179e84 da557000 00000004 da557204 de0c6800 df179e84 [ 1384.972253] 9d80: da557000 00000004 da557204 c0526b7c 00000004 df724000 df179e84 00000004 [ 1384.972260] 9da0: df179db0 df29a100 c083bc48 c045481c 00000001 00000000 00000000 00000000 [ 1384.972267] 9dc0: 00000000 df29a100 00000000 00000000 00000000 00000000 df179e10 00000000 [ 1384.972274] 9de0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 [ 1384.972281] 9e00: 00000000 00000000 00000000 00000000 df179e4c c000ec80 c0b538c0 00000004 [ 1384.972288] 9e20: df724000 df178000 00000000 df179e84 c0b538c0 00000000 df178000 c07f4570 [ 1384.972295] 9e40: dcad9c00 df179e74 c07f4394 df179e60 df178000 00000000 df179e84 de247010 [ 1384.972303] 9e60: 00000043 c0454dec 00000001 00000004 df315c00 c0530598 00000004 df315c0c [ 1384.972310] 9e80: ffffc32c 00000000 00000000 df179ea0 00000001 00000000 00000000 00000000 [ 1384.972317] 9ea0: df179ebc 00000004 df315c00 c05df838 00000000 c0530810 c07d08c0 d7017303 [ 1384.972325] 9ec0: 6ec245b9 00000000 df315c00 c0531b04 c07f3fe0 c07f4018 da67a300 df315c00 [ 1384.972332] 9ee0: 00000000 c05334e0 df315c00 df315b80 df315c00 de0c6800 da67a300 00000000 [ 1384.972339] 9f00: de0c684c c0533674 df204100 df315c00 df315c00 df204100 df315c00 c082b138 [ 1384.972347] 9f20: c053385c c0533754 a0000113 df178000 00000001 c083bc48 00000000 c053385c [ 1384.972354] 9f40: 00000000 00000000 00000000 c05338c4 00000000 df9f0000 df9f5ee4 df179f6c [ 1384.972360] 9f60: df178000 c0049db4 00000000 00000000 c07f3ff8 00000000 00000000 00000000 [ 1384.972368] 9f80: df179f80 df179f80 00000000 00000000 df179f90 df179f90 df9f5ee4 c0049cfc [ 1384.972374] 9fa0: 00000000 00000000 00000000 c000f168 00000000 00000000 00000000 00000000 [ 1384.972381] 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 [ 1384.972388] 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000 00010000 00000600 [ 1384.972411] [] (l2cap_create_basic_pdu+0x30/0x1ac) from [] (l2cap_chan_send+0x100/0x1d4) [ 1384.972425] [] (l2cap_chan_send+0x100/0x1d4) from [] (l2cap_sock_sendmsg+0xa8/0x104) [ 1384.972440] [] (l2cap_sock_sendmsg+0xa8/0x104) from [] (sock_sendmsg+0xac/0xcc) [ 1384.972453] [] (sock_sendmsg+0xac/0xcc) from [] (kernel_sendmsg+0x2c/0x34) [ 1384.972469] [] (kernel_sendmsg+0x2c/0x34) from [] (rfcomm_send_frame+0x58/0x7c) [ 1384.972481] [] (rfcomm_send_frame+0x58/0x7c) from [] (rfcomm_send_ua+0x98/0xbc) [ 1384.972494] [] (rfcomm_send_ua+0x98/0xbc) from [] (rfcomm_recv_disc+0xac/0x100) [ 1384.972506] [] (rfcomm_recv_disc+0xac/0x100) from [] (rfcomm_recv_frame+0x144/0x264) [ 1384.972519] [] (rfcomm_recv_frame+0x144/0x264) from [] (rfcomm_process_rx+0x74/0xfc) [ 1384.972531] [] (rfcomm_process_rx+0x74/0xfc) from [] (rfcomm_process_sessions+0x58/0x160) [ 1384.972543] [] (rfcomm_process_sessions+0x58/0x160) from [] (rfcomm_run+0x68/0x110) [ 1384.972558] [] (rfcomm_run+0x68/0x110) from [] (kthread+0xb8/0xbc) [ 1384.972576] [] (kthread+0xb8/0xbc) from [] (ret_from_fork+0x14/0x2c) [ 1384.972586] Code: e3100004 e1a07003 e5946000 1a000057 (e5969008) [ 1384.972614] ---[ end trace 6170b7ce00144e8c ]--- Signed-off-by: Seung-Woo Kim Signed-off-by: Johan Hedberg --- net/bluetooth/l2cap_core.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index 63fa11109a1c..11b5d097f602 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -2452,6 +2452,9 @@ int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len, int err; struct sk_buff_head seg_queue; + if (!chan->conn) + return -ENOTCONN; + /* Connectionless channel */ if (chan->chan_type == L2CAP_CHAN_CONN_LESS) { skb = l2cap_create_connless_pdu(chan, msg, len, priority);