Re: [patch 04/13] param_sysfs_builtin memchr argument fix

[Jan Kiszka <jan.kiszka@web.de>]

Chuck Ebbert wrote:
> On 11/15/2007 12:58 PM, Greg KH wrote:
>> On Thu, Nov 15, 2007 at 11:11:59AM -0500, Chuck Ebbert wrote:
>>> On 11/15/2007 01:09 AM, Greg KH wrote:
>>>> -stable review patch.  If anyone has any objections, please let us know.
>>>>
>>>> ------------------
>>>> From: Dave Young <hidave.darkstar@gmail.com>
>>>>
>>>> patch faf8c714f4508207a9c81cc94dafc76ed6680b44 in mainline.
>>>>
>>>> If memchr argument is longer than strlen(kp->name), there will be some
>>>> weird result.
>>>>
>>>> It will casuse duplicate filenames in sysfs for the "nousb".  kernel
>>>> warning messages are as bellow:
>>>>
>>> Needs an additional fix:
>>>
>>> Commit:     22800a2830ec07e7cc5c837999890ac47cc7f5de
>>> fix param_sysfs_builtin name length check
>> That just went in yesterday, right?  If so, it will have to wait until
>> the next -stable review cycle, unless it's totally broken without that
>> change.
>>
>> Is it?
>>
> 
> Yeah, pretty much AFAICT. Maybe Jan can say exactly what happened, but
> it looks like the patch would cause more problems than it solves.
> 

If you have a module parameter like
"my_module.uses_long_parameter_names", Dave's patch caused it to be
rejected if that module was built into the kernel, although "my_module"
is far shorter than MAX_KBUILD_MODNAME, thus perfectly legal.

I noticed this with out-of-tree stuff, but I would bet in-tree users are
affected as well. Hmm... e.g. "nf_conntrack.expect_hashsize" should not
longer exist if nf_conntrack is non-modular.

Jan

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