Re: [bug, netconsole, SLUB] BUG skbuff_head_cache: Poison overwritten

Ingo Molnar
2008-07-21T09:41:54Z

update about this problem: just triggered another colorful crash, see
below. This was with the 4K object dump patch already, maybe the dump
gives a clue?

The upstream base of this test kernel was v2.6.26-5253-g14b395e - i.e.
post the big networking pull, but this problem predates it. (It first
triggered after v2.6.26)

All the crashes trigger in or close to networking code - not a single
block IO DMA or other DMA crash happened so far, and no filesystem
corruptions or anything like that which would signal hw trouble.

Ingo

------------------>
initcall sctp_init+0x0/0x697 returned 0 after 9 msecs
calling powernowk8_init+0x0/0x6e
initcall powernowk8_init+0x0/0x6e returned -19 after 0 msecs
calling hpet_insert_resource+0x0/0x1e
initcall hpet_insert_resource+0x0/0x1e returned 0 after 0 msecs
calling lapic_insert_resource+0x0/0x44
initcall lapic_insert_resource+0x0/0x44 returned 0 after 0 msecs
calling init_lapic_nmi_sysfs+0x0/0x33
initcall init_lapic_nmi_sysfs+0x0/0x33 returned 0 after 0 msecs
=============================================================================
BUG skbuff_head_cache: Poison overwritten
-----------------------------------------------------------------------------

INFO: 0xf7ccc100-0xf7ccc103. First byte 0x0 instead of 0x6b
INFO: Allocated in __alloc_skb+0x30/0x10e age=1 cpu=1 pid=1
INFO: Freed in __kfree_skb+0x63/0x66 age=1 cpu=0 pid=0
INFO: Slab 0xc1c34ca0 objects=16 used=1 fp=0xf7ccc100 flags=0x400000c3
INFO: Object 0xf7ccc100 @offset=256 fp=0xf7ccc200

Bytes b4 0xf7ccc0f0: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZZZZZ
Object 0xf7ccc100: 00 00 00 00 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b ....kkkkkkkkkkkk
Object 0xf7ccc110: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object 0xf7ccc120: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object 0xf7ccc130: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object 0xf7ccc140: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object 0xf7ccc150: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object 0xf7ccc160: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object 0xf7ccc170: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object 0xf7ccc180: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object 0xf7ccc190: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Object 0xf7ccc1a0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b a5 kkkkkkkkkkkkkkk�
Redzone 0xf7ccc1b0: bb bb bb bb ����
Padding 0xf7ccc1d8: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZZZZZ
Padding 0xf7ccc1e8: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZZZZZ
Padding 0xf7ccc1f8: 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZ
Pid: 1, comm: swapper Not tainted 2.6.26-tip #3261
[<c01673ad>] print_trailer+0xd1/0xd9
[<c0167428>] check_bytes_and_report+0x73/0x8f
[<c0167664>] check_object+0xa5/0x15a
[<c016824c>] __slab_alloc+0x2fb/0x3c8
[<c0168364>] kmem_cache_alloc+0x4b/0xa8
[<c0497376>] ? __alloc_skb+0x30/0x10e
[<c0497376>] ? __alloc_skb+0x30/0x10e
[<c0497376>] __alloc_skb+0x30/0x10e
[<c04a6678>] alloc_skb+0xc/0xe
[<c04a6ce5>] find_skb+0x28/0x66
[<c04a6f5f>] netpoll_send_udp+0x2b/0x1cf
[<c058800f>] ? _spin_lock_irqsave+0x4b/0x55
[<c03db399>] write_msg+0x79/0xac
[<c03db320>] ? write_msg+0x0/0xac
[<c0122f96>] __call_console_drivers+0x56/0x63
[<c0122ffa>] _call_console_drivers+0x57/0x5b
[<c0123386>] release_console_sem+0x112/0x1a5
[<c01238f3>] vprintk+0x344/0x35e