Re: slub error in fs/sysfs/bin.c related code

From: Greg Kroah-Hartman
Date: Thu Feb 28 2013 - 11:27:42 EST


On Thu, Feb 28, 2013 at 11:03:58AM -0500, Sasha Levin wrote:
> Hi Greg,
>
> While fuzzing with trinity inside a KVM tools guest, running latest -next kernel
> I got the following spew.
>
> The open() and release() callbacks in the traces below point to fs/sysfs/bin.c.

Any hint as to which sysfs binary file you were accessing when this
happened?

> [ 719.288925] =============================================================================
> [ 719.290663] BUG kmalloc-4096 (Tainted: G W ): Redzone overwritten
> [ 719.291764] -----------------------------------------------------------------------------
> [ 719.291764]
> [ 719.294527] Disabling lock debugging due to kernel taint
> [ 719.294527] INFO: 0xffff88006d1a5520-0xffff88006d1a5520. First byte 0x0 instead of 0xcc
> [ 719.294527] INFO: Allocated in open+0xb8/0x190 age=18922 cpu=1 pid=7095
> [ 719.294527] __slab_alloc+0x622/0x6d0
> [ 719.294527] kmem_cache_alloc_trace+0x123/0x2c0
> [ 719.294527] open+0xb8/0x190
> [ 719.294527] do_dentry_open+0x229/0x330
> [ 719.294527] finish_open+0x54/0x70
> [ 719.294527] do_last+0x56c/0x790
> [ 719.294527] path_openat+0xbe/0x490
> [ 719.294527] do_filp_open+0x44/0xa0
> [ 719.294527] do_sys_open+0x133/0x1d0
> [ 719.294527] sys_open+0x1c/0x20
> [ 719.294527] tracesys+0xdd/0xe2
> [ 719.294527] INFO: Freed in seq_release+0x18/0x30 age=18947 cpu=0 pid=31203
> [ 719.294527] __slab_free+0x3c/0x590
> [ 719.294527] kfree+0x2cb/0x2e0
> [ 719.294527] seq_release+0x18/0x30
> [ 719.294527] single_release+0x24/0x40
> [ 719.294527] proc_reg_release+0xed/0x110
> [ 719.294527] __fput+0x122/0x2d0
> [ 719.294527] ____fput+0x9/0x10
> [ 719.294527] task_work_run+0xbe/0x100
> [ 719.294527] do_notify_resume+0x7e/0xa0
> [ 719.294527] int_signal+0x12/0x17
> [ 719.294527] INFO: Slab 0xffffea0001b46800 objects=7 used=7 fp=0x (null) flags=0x1ffc0000004081
> [ 719.294527] INFO: Object 0xffff88006d1a4520 @offset=17696 fp=0x (null)

Hm, where is sysfs in this traceback? I don't see it mentioned anywhere
in this report, what am I missing?

thanks,

greg k-h
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