[Openswan Users] BUG: unable to handle kernel NULL pointer -- 2.6.33 w/ |KLIPS

Mon May 2 09:55:19 EDT 2011

Hi Paul,

On 26 Apr 2011, at 19:53, Paul Wouters wrote:

> On Tue, 26 Apr 2011, Lawrence Manning wrote:
> 
>> I'm seeing a strange kernel panic at ipsec start on the following:
>> 
>> Kernel 2.6.32.26 with Ubuntu 10.4 LTS patches, Openswan 2.6.33.
> 
> 2.6.34dr2 (in the development/ directory on the ftp server) has a few
> KLIPS fixes. You can try that, though the crasher here looks unknown to me.

I've boiled the crash down to something reproducible.

Kernel is vanilla 2.6.32, with openswan 2.6.34dr2.  Single PSK tunnel (this is a test setup with virtualbox).

Steps:

1. Bring up the tunnel, test tunnel etc.  Everything is great.
2. With the tunnel up, ifconfig the external interface down.
3. Send a ping down the tunnel.
4. ifconfig the external up.
5. Panic results.

If I don't send any packets between the down and the up of the external interface, then no panic results.

I know this is a slightly "odd" scenario.  However no panic should result like this.

Should I try other kernels?  I really don't want to switch from this kernel though.

Here's the panic text.  Though there are differences, I'm pretty sure it's the same underlying cause.

BUG: unable to handle kernel NULL pointer dereference at 000000d0
IP: [<c11defcd>] netif_receive_skb+0x79/0x29e
*pdpt = 000000000e7b2001 *pde = 0000000000000000 
Oops: 0000 [#1] SMP 
last sysfs file: /sys/kernel/uevent_seqnum
Modules linked in: ipsec deflate zlib_deflate serpent blowfish twofish twofish_common ecb cbc md5 sha256_generic sha512_generic des_generic aes_i586 aes_generic geode_aes cryptomgr aead pcompress crypto_blkcipher crc32c libcrc32c crypto_hash crypto_algapi uio mlx4_core e1000 libphy sungem_phy 8390 i2c_algo_bit i2c_core mdio ssb mii tun nf_nat_ftp nf_conntrack_ftp xt_mod xt_CONNMARK xt_length xt_tcpudp xt_mark xt_owner xt_iprange xt_dscp xt_ipp2p xt_connmark xt_multiport xt_state xt_NOTRACK xt_MARK xt_DSCP xt_CLASSIFY xt_ACCOUNT compat_xtables ipt_MASQUERADE ipt_REDIRECT ipt_REJECT ipt_LOG iptable_raw iptable_mangle iptable_nat nf_nat nf_conntrack_ipv4 nf_conntrack nf_defrag_ipv4 iptable_filter ip_tables x_tables ppp_async crc_ccitt ppp_synctty ppp_generic slhc bonding 8021q usb_storage vfat msdos fat loop raid1 usbhid ata_generic ahci ohci_hcd ata_piix pata_acpi ehci_hcd usbcore [last unloaded: ip_queue]

Pid: 5542, comm: ifconfig Not tainted (2.6.32-0-smp #1) VirtualBox
EIP: 0060:[<c11defcd>] EFLAGS: 00010202 CPU: 0
EIP is at netif_receive_skb+0x79/0x29e
EAX: 00000000 EBX: cedd7780 ECX: 00000000 EDX: 00000000
ESI: c1a039e0 EDI: c1a03a00 EBP: ce709da8 ESP: ce709d8c
 DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
Process ifconfig (pid: 5542, ti=ce708000 task=cf4e7890 task.ti=ce708000)
Stack:
 ce91f901 00000001 00000000 00000000 00000001 c1a039e0 c1a03a00 ce709dc4
<0> c11df8ad ffff6d23 00000040 c1a03a00 00000100 c1a039f4 ce709dec c11dfa8a
<0> 00000040 00000000 0000011c ffff6d25 ce7aaf40 00000003 00000100 00000001
Call Trace:
 [<c11df8ad>] ? process_backlog+0x7f/0x97
 [<c11dfa8a>] ? net_rx_action+0x76/0x130
 [<c102c7e8>] ? __do_softirq+0x80/0xf3
 [<c102c88c>] ? do_softirq+0x31/0x3c
 [<c102c90e>] ? irq_exit+0x2d/0x2f
 [<c1009f0b>] ? do_IRQ+0x7d/0x93
 [<c1008569>] ? common_interrupt+0x29/0x30
 [<d103015b>] ? e1000_irq_enable+0x2b/0x70 [e1000]
 [<d1030af4>] ? e1000_open+0x94/0x140 [e1000]
 [<c11dde2b>] ? dev_open+0x95/0xcd
 [<c11e0f22>] ? dev_change_flags+0x96/0x150
 [<c12193e4>] ? devinet_ioctl+0x21f/0x47d
 [<c121afb3>] ? inet_ioctl+0x52/0x6b
 [<c11d3553>] ? sock_ioctl+0x1ae/0x1d2
 [<c11d33a5>] ? sock_ioctl+0x0/0x1d2
 [<c107d43f>] ? vfs_ioctl+0x27/0x68
 [<c107def7>] ? do_vfs_ioctl+0x16f/0x17a
 [<c107df2e>] ? sys_ioctl+0x2c/0x46
 [<c1007f6d>] ? syscall_call+0x7/0xb
Code: e8 33 bb 07 00 31 d2 85 c0 0f 85 37 02 00 00 83 7b 78 00 75 09 8b 43 14 8b 40 48 89 43 78 c7 45 ec 00 00 00 00 8b 43 14 89 45 f0 <8b> b0 d0 00 00 00 85 f6 0f 84 9d 00 00 00 0f b7 96 be 00 00 00 
EIP: [<c11defcd>] netif_receive_skb+0x79/0x29e SS:ESP 0068:ce709d8c
CR2: 00000000000000d0
---[ end trace 1c7e9c566ad9c70c ]---
Kernel panic - not syncing: Fatal exception in interrupt
Pid: 5542, comm: ifconfig Tainted: G      D    2.6.32-0-smp #1
Call Trace:
 [<c10286e3>] panic+0x38/0xe2
 [<c100ae05>] oops_end+0x74/0x82
 [<c10195a7>] no_context+0xbc/0xc4
 [<c10196b6>] __bad_area_nosemaphore+0x107/0x10f
 [<c10196cb>] bad_area_nosemaphore+0xd/0xf
 [<c1019ab7>] do_page_fault+0xf6/0x1fb
 [<c10199c1>] ? do_page_fault+0x0/0x1fb
 [<c126947e>] error_code+0x66/0x6c
 [<c10199c1>] ? do_page_fault+0x0/0x1fb
 [<c11defcd>] ? netif_receive_skb+0x79/0x29e
 [<c11df8ad>] process_backlog+0x7f/0x97
 [<c11dfa8a>] net_rx_action+0x76/0x130
 [<c102c7e8>] __do_softirq+0x80/0xf3
 [<c102c88c>] do_softirq+0x31/0x3c
 [<c102c90e>] irq_exit+0x2d/0x2f
 [<c1009f0b>] do_IRQ+0x7d/0x93
 [<c1008569>] common_interrupt+0x29/0x30
 [<d103015b>] ? e1000_irq_enable+0x2b/0x70 [e1000]
 [<d1030af4>] e1000_open+0x94/0x140 [e1000]
 [<c11dde2b>] dev_open+0x95/0xcd
 [<c11e0f22>] dev_change_flags+0x96/0x150
 [<c12193e4>] devinet_ioctl+0x21f/0x47d
 [<c121afb3>] inet_ioctl+0x52/0x6b
 [<c11d3553>] sock_ioctl+0x1ae/0x1d2
 [<c11d33a5>] ? sock_ioctl+0x0/0x1d2
 [<c107d43f>] vfs_ioctl+0x27/0x68
 [<c107def7>] do_vfs_ioctl+0x16f/0x17a
 [<c107df2e>] sys_ioctl+0x2c/0x46
 [<c1007f6d>] syscall_call+0x7/0xb

-- 

Lawrence Manning
Lead Developer

lawrence.manning at smoothwall.net

Smoothwall Ltd
1 John Charles Way, Leeds, LS12 6QA United Kingdom 
Telephone:  USA: 1 800 959 3760  Europe: +44 (0) 8701 999500
www.smoothwall.net

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