tcp: Fix NULL dereference in tcp_4_send_ack()
Fix NULL dereference in tcp_4_send_ack().
As skb->dev is reset to NULL in tcp_v4_rcv() thus OOPS occurs:
BUG: unable to handle kernel NULL pointer dereference at 00000000000004d0
IP: [<ffffffff80498503>] tcp_v4_send_ack+0x203/0x250
Stack: ffff810005dbb000 ffff810015c8acc0 e77b2c6e5f861600 a01610802e90cb6d
0a08010100000000 88afffff88afffff 0000000080762be8 0000000115c872e8
0004122000000000 0000000000000001 ffffffff80762b88 0000000000000020
Call Trace:
<IRQ> [<ffffffff80499c33>] tcp_v4_reqsk_send_ack+0x20/0x22
[<ffffffff8049bce5>] tcp_check_req+0x108/0x14c
[<ffffffff8047aaf7>] ? rt_intern_hash+0x322/0x33c
[<ffffffff80499846>] tcp_v4_do_rcv+0x399/0x4ec
[<ffffffff8045ce4b>] ? skb_checksum+0x4f/0x272
[<ffffffff80485b74>] ? __inet_lookup_listener+0x14a/0x15c
[<ffffffff8049babc>] tcp_v4_rcv+0x6a1/0x701
[<ffffffff8047e739>] ip_local_deliver_finish+0x157/0x24a
[<ffffffff8047ec9a>] ip_local_deliver+0x72/0x7c
[<ffffffff8047e5bd>] ip_rcv_finish+0x38d/0x3b2
[<ffffffff803d3548>] ? scsi_io_completion+0x19d/0x39e
[<ffffffff8047ebe5>] ip_rcv+0x2a2/0x2e5
[<ffffffff80462faa>] netif_receive_skb+0x293/0x303
[<ffffffff80465a9b>] process_backlog+0x80/0xd0
[<ffffffff802630b4>] ? __rcu_process_callbacks+0x125/0x1b4
[<ffffffff8046560e>] net_rx_action+0xb9/0x17f
[<ffffffff80234cc5>] __do_softirq+0xa3/0x164
[<ffffffff8020c52c>] call_softirq+0x1c/0x28
<EOI> [<ffffffff8020de1c>] do_softirq+0x34/0x72
[<ffffffff80234b8e>] local_bh_enable_ip+0x3f/0x50
[<ffffffff804d43ca>] _spin_unlock_bh+0x12/0x14
[<ffffffff804599cd>] release_sock+0xb8/0xc1
[<ffffffff804a6f9a>] inet_stream_connect+0x146/0x25c
[<ffffffff80243078>] ? autoremove_wake_function+0x0/0x38
[<ffffffff8045751f>] sys_connect+0x68/0x8e
[<ffffffff80291818>] ? fd_install+0x5f/0x68
[<ffffffff80457784>] ? sock_map_fd+0x55/0x62
[<ffffffff8020b39b>] system_call_after_swapgs+0x7b/0x80
Code: 41 10 11 d0 83 d0 00 4d 85 ed 89 45 c0 c7 45 c4 08 00 00 00 74 07 41 8b 45 04 89 45 c8 48 8b 43 20 8b 4d b8 48 8d 55 b0 48 89 de <48> 8b 80 d0 04 00 00 48 8b b8 60 01 00 00 e8 20 ae fe ff 65 48
RIP [<ffffffff80498503>] tcp_v4_send_ack+0x203/0x250
RSP <ffffffff80762b78>
CR2: 00000000000004d0
Signed-off-by: Vitaliy Gusev <vgusev@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 file changed