[linux-cifs-client] oops in khelper

[Vasily Averin]

Hello Steve,

Could you please take a look at the following oops? It looks like it is related
to cifs:
1) Code line is corrupted (21 byte?!?), It looks like part of CIFS smb_hdr with
 CIFS magic:
 00 00 50 ff 53 4d 42 32 00 00 00 00 80 41 c0 <00> 00 00 00 00 00
          FF S  M  B

2) This issue was reproduced several times on several nodes, but every time it
was occurred after the following message:

"CIFS VFS: Invalid size SMB length 4 pdu_length 4"

Is it probably known issue for you?

Thank you,
	Vasily Averin

Virtuozzo/OpenVZ linux kernel Team

Unable to handle kernel NULL pointer dereference at virtual address 00000611
 printing eip:
02106330
*pde = 00004001
Oops: 0002 [#1]
SMP
Modules linked in: nls_iso8859_1 cifs simfs mptctl vzrst vzcpt ip_vzredir
vzredir vzcompat vzdquota vzfs vzethdev vzevent vzlist vzstat ip_vznetstat
af_packet 8021q bridge vznet vznetstat vzmon vzdev iptable_filter tun ipt_mac
ipt_MASQUERADE ip_nat_irc ip_nat_ftp iptable_nat ip_conntrack_irc
ip_conntrack_ftp ipt_LOG ipt_state ip_conntrack ipt_length ipt_ttl ipt_tcpmss
ipt_TCPMSS iptable_mangle ipt_multiport ipt_limit ipt_tos ipt_REJECT ip_tables
thermal processor fan button battery ac uhci_hcd ehci_hcd e752x_edac edac_mc
e1000 sg
CPU:    2, VCPU: 0:1
EIP:    0060:[<02106330>]    Tainted:  P      VLI
EFLAGS: 00010202   (2.6.9-023stab044.4-enterprise)
EIP is at kernel_thread+0x0/0xd0
eax: 00000611   ebx: ca969e68   ecx: ca969e28   edx: 00000206
esi: 08109000   edi: ca969e2c   ebp: 00000206   esp: 0814bf30
ds: 007b   es: 007b   ss: 0068
Process khelper (pid: 14, veid=0, threadinfo=0814a000 task=08147360)
Stack: 0213f828 0213f750 ca969e68 00000611 ca969e68 0213fe33 ca969e68 0814bf74
       00000000 08109028 08109010 08109018 0213f800 ca969e28 0814a000 ffffffff
       ffffffff 00000001 00000000 02123680 00010000 00000000 e1f718c0 ffffffff
Call Trace:
 [<0213f828>] __call_usermodehelper+0x28/0x70
 [<0213f750>] wait_for_helper+0x0/0xb0
 [<0213fe33>] worker_thread+0x1f3/0x280
 [<0213f800>] __call_usermodehelper+0x0/0x70
 [<02123680>] default_wake_function+0x0/0x20
 [<02123680>] default_wake_function+0x0/0x20
 [<0213fc40>] worker_thread+0x0/0x280
 [<02144d6d>] kthread+0xbd/0x100
 [<02144cb0>] kthread+0x0/0x100
 [<02106321>] kernel_thread_helper+0x5/0x14
Code: 24 ec 64 50 02 89 44 24 04 e8 1d 64 02 00 83 c4 18 5b 5e 5f c3 89 f6 89 d0
52 ff d3 00 00 50 ff 53 4d 42 32 00 00 00 00 80 41 c0 <00> 00 00 00 00 00 e5 6c
02 8b 54 24 68 85 c0 75 19 b8 00 e0 ff


Oct 20 03:51:05 kernel:  CIFS VFS: Invalid size SMB length 4 pdu_length 4
Oct 20 03:51:05 kernel:  CIFS VFS: No response for cmd 50 mid 17053
Oct 20 03:52:37 kernel: Unable to handle kernel NULL pointer dereference at
virtual address 00000611

Oct 26 00:50:22 s39 kernel:  CIFS VFS: Invalid size SMB length 4 pdu_length 4
Oct 26 00:50:22 s39 kernel:  CIFS VFS: No response for cmd 50 mid 32013
Oct 26 00:50:40 s39 kernel: Unable to handle kernel NULL pointer dereference at
virtual address 00000611

Nov  5 03:50:18 s39 kernel:  CIFS VFS: Invalid size SMB length 4 pdu_length 4
Nov  5 03:50:18 s39 kernel:  CIFS VFS: No response for cmd 50 mid 10169
Nov  5 03:50:39 s39 kernel: Unable to handle kernel NULL pointer dereference at
virtual address 00000611