linux-sg2042/net/dccp
Gui Jianfeng 6edafaaf6f tcp: Fix kernel panic when calling tcp_v(4/6)_md5_do_lookup
If the following packet flow happen, kernel will panic.
MathineA			MathineB
		SYN
	---------------------->    
        	SYN+ACK
	<----------------------
		ACK(bad seq)
	---------------------->
When a bad seq ACK is received, tcp_v4_md5_do_lookup(skb->sk, ip_hdr(skb)->daddr))
is finally called by tcp_v4_reqsk_send_ack(), but the first parameter(skb->sk) is 
NULL at that moment, so kernel panic happens.
This patch fixes this bug.

OOPS output is as following:
[  302.812793] IP: [<c05cfaa6>] tcp_v4_md5_do_lookup+0x12/0x42
[  302.817075] Oops: 0000 [#1] SMP 
[  302.819815] Modules linked in: ipv6 loop dm_multipath rtc_cmos rtc_core rtc_lib pcspkr pcnet32 mii i2c_piix4 parport_pc i2c_core parport ac button ata_piix libata dm_mod mptspi mptscsih mptbase scsi_transport_spi sd_mod scsi_mod crc_t10dif ext3 jbd mbcache uhci_hcd ohci_hcd ehci_hcd [last unloaded: scsi_wait_scan]
[  302.849946] 
[  302.851198] Pid: 0, comm: swapper Not tainted (2.6.27-rc1-guijf #5)
[  302.855184] EIP: 0060:[<c05cfaa6>] EFLAGS: 00010296 CPU: 0
[  302.858296] EIP is at tcp_v4_md5_do_lookup+0x12/0x42
[  302.861027] EAX: 0000001e EBX: 00000000 ECX: 00000046 EDX: 00000046
[  302.864867] ESI: ceb69e00 EDI: 1467a8c0 EBP: cf75f180 ESP: c0792e54
[  302.868333]  DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
[  302.871287] Process swapper (pid: 0, ti=c0792000 task=c0712340 task.ti=c0746000)
[  302.875592] Stack: c06f413a 00000000 cf75f180 ceb69e00 00000000 c05d0d86 000016d0 ceac5400 
[  302.883275]        c05d28f8 000016d0 ceb69e00 ceb69e20 681bf6e3 00001000 00000000 0a67a8c0 
[  302.890971]        ceac5400 c04250a3 c06f413a c0792eb0 c0792edc cf59a620 cf59a620 cf59a634 
[  302.900140] Call Trace:
[  302.902392]  [<c05d0d86>] tcp_v4_reqsk_send_ack+0x17/0x35
[  302.907060]  [<c05d28f8>] tcp_check_req+0x156/0x372
[  302.910082]  [<c04250a3>] printk+0x14/0x18
[  302.912868]  [<c05d0aa1>] tcp_v4_do_rcv+0x1d3/0x2bf
[  302.917423]  [<c05d26be>] tcp_v4_rcv+0x563/0x5b9
[  302.920453]  [<c05bb20f>] ip_local_deliver_finish+0xe8/0x183
[  302.923865]  [<c05bb10a>] ip_rcv_finish+0x286/0x2a3
[  302.928569]  [<c059e438>] dev_alloc_skb+0x11/0x25
[  302.931563]  [<c05a211f>] netif_receive_skb+0x2d6/0x33a
[  302.934914]  [<d0917941>] pcnet32_poll+0x333/0x680 [pcnet32]
[  302.938735]  [<c05a3b48>] net_rx_action+0x5c/0xfe
[  302.941792]  [<c042856b>] __do_softirq+0x5d/0xc1
[  302.944788]  [<c042850e>] __do_softirq+0x0/0xc1
[  302.948999]  [<c040564b>] do_softirq+0x55/0x88
[  302.951870]  [<c04501b1>] handle_fasteoi_irq+0x0/0xa4
[  302.954986]  [<c04284da>] irq_exit+0x35/0x69
[  302.959081]  [<c0405717>] do_IRQ+0x99/0xae
[  302.961896]  [<c040422b>] common_interrupt+0x23/0x28
[  302.966279]  [<c040819d>] default_idle+0x2a/0x3d
[  302.969212]  [<c0402552>] cpu_idle+0xb2/0xd2
[  302.972169]  =======================
[  302.974274] Code: fc ff 84 d2 0f 84 df fd ff ff e9 34 fe ff ff 83 c4 0c 5b 5e 5f 5d c3 90 90 57 89 d7 56 53 89 c3 50 68 3a 41 6f c0 e8 e9 55 e5 ff <8b> 93 9c 04 00 00 58 85 d2 59 74 1e 8b 72 10 31 db 31 c9 85 f6 
[  303.011610] EIP: [<c05cfaa6>] tcp_v4_md5_do_lookup+0x12/0x42 SS:ESP 0068:c0792e54
[  303.018360] Kernel panic - not syncing: Fatal exception in interrupt

Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-06 23:50:04 -07:00
..
ccids dccp ccid-3: Length of loss intervals 2008-07-13 11:51:40 +01:00
Kconfig [DCCP]: Promote CCID2 as default CCID 2008-01-28 14:54:46 -08:00
Makefile [DCCPv6]: Resolve conditional build problem 2006-12-02 21:22:28 -08:00
ackvec.c dccp: Fix sparse warnings 2008-06-11 11:19:09 +01:00
ackvec.h [ACKVEC]: Reduce length of identifiers 2008-01-28 14:54:51 -08:00
ccid.c [CCID]: More informative registration 2008-01-28 14:57:58 -08:00
ccid.h [DCCP]: Introducing CCMPS 2008-01-28 14:57:59 -08:00
dccp.h tcp: Fix kernel panic when calling tcp_v(4/6)_md5_do_lookup 2008-08-06 23:50:04 -07:00
diag.c [INET]: Let inet_diag and friends autoload 2007-10-22 02:59:54 -07:00
feat.c dccp: return -EINVAL on invalid feature length 2008-05-05 13:50:24 -07:00
feat.h [DCCP]: Remove unused and redundant validation functions 2008-01-28 14:57:52 -08:00
input.c net: convert BUG_TRAP to generic WARN_ON 2008-07-25 21:43:18 -07:00
ipv4.c dccp: Fix incorrect length check for ICMPv4 packets 2008-07-26 11:59:10 +01:00
ipv6.c dccp: Add check for truncated ICMPv6 DCCP error packets 2008-07-26 11:59:11 +01:00
ipv6.h Remove obsolete #include <linux/config.h> 2006-06-30 19:25:36 +02:00
minisocks.c tcp: Fix kernel panic when calling tcp_v(4/6)_md5_do_lookup 2008-08-06 23:50:04 -07:00
options.c dccp: Upgrade NDP count from 3 to 6 bytes 2008-07-13 11:51:40 +01:00
output.c dccp: Bug-Fix - AWL was never updated 2008-07-26 11:59:10 +01:00
probe.c dccp: Fix sparse warnings 2008-06-11 11:19:09 +01:00
proto.c net: convert BUG_TRAP to generic WARN_ON 2008-07-25 21:43:18 -07:00
sysctl.c [NET]: Simple ctl_table to ctl_path conversions. 2008-01-28 15:01:07 -08:00
timer.c dccp: Allow to distinguish original and retransmitted packets 2008-07-26 11:59:09 +01:00