Crash in network stack

[Naveen B N (nbn)]

Hi All
I am trying to edit esp flow in kernel , I have edited the ip_rcv() , just to avoid xfrm look up
For ipsec processing I have a simple database for storing xfrm_state values.
In ip_rcv() I have decrypted the ESP packet and I am calling netif_rx(skb) , I am successfully
Able to receive the packet in user space , where the user application is listening on Inner Ip
Address. But kernel crashes if I send multiple packets .
I am unable to figure out this , I am using user mode kernel, host linux is 2.6.34 version,
Same code base is used to build UML kernel, x86.

I am attaching the net/ipv4/ip_input.c file , Please help me to figure out this crash.

Kernel panic - not syncing: Kernel mode signal 4
0823c748: [<081beb4b>] dump_stack+0x1c/0x20
0823c760: [<081beb84>] panic+0x35/0x9d
0823c788: [<0805a107>] relay_signal+0x31/0x6c
0823c7a8: [<08065a9a>] sig_handler_common+0x61/0x70
0823c820: [<08065bc2>] sig_handler+0x31/0x3d
0823c82c: [<08065d5b>] handle_signal+0x4f/0x7d
0823c84c: [<080673f7>] hard_handler+0xf/0x14
0823c85c: [<b783d400>] 0xb783d400
0823cb7c: [<080b3772>] __kmalloc+0x70/0x9c
0823cb9c: [<0816b95d>] __alloc_skb+0x52/0x11c
0823cbc8: [<0816c344>] dev_alloc_skb+0x15/0x2c
0823cbe0: [<0805e871>] uml_net_rx+0x19/0x9e
0823cbfc: [<0805e9d9>] uml_net_interrupt+0x16/0x5c
0823cc08: [<080947d0>] handle_IRQ_event+0x20/0xa7
0823cc24: [<080948aa>] __do_IRQ+0x53/0x93
0823cc40: [<080581a8>] do_IRQ+0x1f/0x34
0823cc50: [<08058340>] sigio_handler+0x46/0x5c
0823cc68: [<08065a9a>] sig_handler_common+0x61/0x70
0823cce0: [<08065bc2>] sig_handler+0x31/0x3d
0823ccec: [<08065d5b>] handle_signal+0x4f/0x7d
0823cd0c: [<080673f7>] hard_handler+0xf/0x14
0823cd1c: [<b783d400>] 0xb783d400



EIP: 0073:[<b7723861>] CPU: 0 Tainted: P ESP: 007b:bfe1cbfc EFLAGS: 00000246
Tainted: P
EAX: 00000000 EBX: 00006222 ECX: 00000013 EDX: 00006222
ESI: 0000621e EDI: 0000001c EBP: bfe1cc18 DS: 007b ES: 007b
0823c6f8: [<0806aae7>] show_regs+0xc4/0xc9
0823c724: [<0805a70a>] panic_exit+0x25/0x3b
0823c738: [<08086063>] notifier_call_chain+0x27/0x4c
0823c760: [<080860b6>] atomic_notifier_call_chain+0x15/0x17
0823c770: [<081beb9f>] panic+0x50/0x9d
0823c788: [<0805a107>] relay_signal+0x31/0x6c
0823c7a8: [<08065a9a>] sig_handler_common+0x61/0x70
0823c820: [<08065bc2>] sig_handler+0x31/0x3d
0823c82c: [<08065d5b>] handle_signal+0x4f/0x7d
0823c84c: [<080673f7>] hard_handler+0xf/0x14
0823c85c: [<b783d400>] 0xb783d400
0823cb7c: [<080b3772>] __kmalloc+0x70/0x9c
0823cb9c: [<0816b95d>] __alloc_skb+0x52/0x11c
0823cbc8: [<0816c344>] dev_alloc_skb+0x15/0x2c
0823cbe0: [<0805e871>] uml_net_rx+0x19/0x9e
0823cbfc: [<0805e9d9>] uml_net_interrupt+0x16/0x5c
0823cc08: [<080947d0>] handle_IRQ_event+0x20/0xa7
0823cc24: [<080948aa>] __do_IRQ+0x53/0x93
0823cc40: [<080581a8>] do_IRQ+0x1f/0x34
0823cc50: [<08058340>] sigio_handler+0x46/0x5c
0823cc68: [<08065a9a>] sig_handler_common+0x61/0x70
0823cce0: [<08065bc2>] sig_handler+0x31/0x3d
0823ccec: [<08065d5b>] handle_signal+0x4f/0x7d
0823cd0c: [<080673f7>] hard_handler+0xf/0x14
0823cd1c: [<b783d400>] 0xb783d400


Thanks and Regards
Naveen