WARNING: at lib/kref.c:33 kref_get() (-mm 2007-11-06-02-32++)

WARNING: at lib/kref.c:33 kref_get() (-mm 2007-11-06-02-32++)

[Erez Zadok]

Setup: FC6 system with MM snapshot broken-out-2007-11-06-02-32 and these two
patches added:

r-o-bind-mounts-track-number-of-mount-writer-fix-buggy-loop.patch
r-o-bind-mounts-track-number-of-mount-writer-fix-buggy-loop-checkpatch-fixes.patch

Booting the machine, waiting a few minutes (not logging in or doing anything
else).  I get:

WARNING: at lib/kref.c:33 kref_get()
 [<c020282a>] show_trace_log_lvl+0x12/0x25
 [<c0203024>] show_trace+0xd/0x10
 [<c0203120>] dump_stack+0x15/0x17
 [<c02c7f85>] kref_get+0x26/0x30
 [<c02c731b>] kobject_get+0x12/0x17
 [<c02c7770>] kobject_add+0x97/0x162
 [<c02164e5>] uids_user_create+0x41/0x5d
 [<c0216850>] alloc_uid+0xc9/0x171
 [<c0219b50>] set_user+0x1f/0x93
 [<c021b445>] sys_setuid+0x4b/0xcb
 [<c02021fe>] sysenter_past_esp+0x5f/0x91
 =======================

There's no other indication where the setuid(2) came from, perhaps cron?

Erez.

Re: WARNING: at lib/kref.c:33 kref_get() (-mm 2007-11-06-02-32++)

[Andrew Morton]

On Fri, 9 Nov 2007 21:12:47 -0500 Erez Zadok <ezk@cs.sunysb.edu> wrote:

> Setup: FC6 system with MM snapshot broken-out-2007-11-06-02-32

That's a bit old.

> and these two
> patches added:
> 
> r-o-bind-mounts-track-number-of-mount-writer-fix-buggy-loop.patch
> r-o-bind-mounts-track-number-of-mount-writer-fix-buggy-loop-checkpatch-fixes.patch
> 
> Booting the machine, waiting a few minutes (not logging in or doing anything
> else).  I get:
> 
> WARNING: at lib/kref.c:33 kref_get()
>  [<c020282a>] show_trace_log_lvl+0x12/0x25
>  [<c0203024>] show_trace+0xd/0x10
>  [<c0203120>] dump_stack+0x15/0x17
>  [<c02c7f85>] kref_get+0x26/0x30
>  [<c02c731b>] kobject_get+0x12/0x17
>  [<c02c7770>] kobject_add+0x97/0x162
>  [<c02164e5>] uids_user_create+0x41/0x5d
>  [<c0216850>] alloc_uid+0xc9/0x171
>  [<c0219b50>] set_user+0x1f/0x93
>  [<c021b445>] sys_setuid+0x4b/0xcb
>  [<c02021fe>] sysenter_past_esp+0x5f/0x91
>  =======================
> 
> There's no other indication where the setuid(2) came from, perhaps cron?
> 

I have a feeling that this was reported before and that Dave and/or Greg
looked into it.  Were those two patches which Dave sent yesterday applied?

It might be worth checking my current tree:
http://userweb.kernel.org/~akpm/mmotm/

Re: WARNING: at lib/kref.c:33 kref_get() (-mm 2007-11-06-02-32++)

[Erez Zadok]

In message <20071110145452.f6cf6326.akpm@linux-foundation.org>, Andrew Morton writes:
> On Fri, 9 Nov 2007 21:12:47 -0500 Erez Zadok <ezk@cs.sunysb.edu> wrote:
> 
> > Setup: FC6 system with MM snapshot broken-out-2007-11-06-02-32
> 
> That's a bit old.
> 
> > and these two
> > patches added:
> > 
> > r-o-bind-mounts-track-number-of-mount-writer-fix-buggy-loop.patch
> > r-o-bind-mounts-track-number-of-mount-writer-fix-buggy-loop-checkpatch-fixes.patch
> > 
> > Booting the machine, waiting a few minutes (not logging in or doing anything
> > else).  I get:
> > 
> > WARNING: at lib/kref.c:33 kref_get()
> >  [<c020282a>] show_trace_log_lvl+0x12/0x25
> >  [<c0203024>] show_trace+0xd/0x10
> >  [<c0203120>] dump_stack+0x15/0x17
> >  [<c02c7f85>] kref_get+0x26/0x30
> >  [<c02c731b>] kobject_get+0x12/0x17
> >  [<c02c7770>] kobject_add+0x97/0x162
> >  [<c02164e5>] uids_user_create+0x41/0x5d
> >  [<c0216850>] alloc_uid+0xc9/0x171
> >  [<c0219b50>] set_user+0x1f/0x93
> >  [<c021b445>] sys_setuid+0x4b/0xcb
> >  [<c02021fe>] sysenter_past_esp+0x5f/0x91
> >  =======================
> > 
> > There's no other indication where the setuid(2) came from, perhaps cron?
> > 
> 
> I have a feeling that this was reported before and that Dave and/or Greg
> looked into it.  Were those two patches which Dave sent yesterday applied?

Yes, both of Dave's patches were applied.  I'll give the latest -mm a try
first and see report comes up.

> It might be worth checking my current tree:
> http://userweb.kernel.org/~akpm/mmotm/

The above URL is very useful.  Thanks!

I've got comments on my experience w/ the above URL, but I'll send those as
separate emails shortly.

Erez.