Re: Linux 4.2-rc1

[Stephen Smalley <sds@tycho.nsa.gov>]

On 07/08/2015 01:47 PM, Casey Schaufler wrote:
> On 7/8/2015 10:29 AM, Linus Torvalds wrote:
>> On Wed, Jul 8, 2015 at 10:17 AM, Linus Torvalds
>> <torvalds@linux-foundation.org> wrote:
>>> Decoding the "Code:" line shows that this is the "->fw_id" dereference in
>>>
>>>         if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->buf->fw_id))
>>>                 return -ENOMEM;
>>>
>>> and that "fw_priv->buf" pointer is NULL.
>>>
>>> However, I don't see anything that looks like it should have changed
>>> any of this since 4.1.
>> Looking at the otehr uses of "fw_priv->buf", they all check that
>> pointer for NULL. I see code like
>>
>>         fw_buf = fw_priv->buf;
>>         if (!fw_buf)
>>                 goto out;
>>
>> etc.
>>
>> Also, it looks like you need to hold the "fw_lock" to even look at
>> that pointer, since the buffer can get reallocated etc.
>>
>> So that uevent code really looks buggy. It just doesn't look like a
>> *new* bug to me. That code looks old, going back to 2012 and commit
>> 1244691c73b2.
> 
> There have been SELinux changes to kernfs for 4.2. William,
> you might want to have a look here.

What change are you referring to?  I see no SELinux-related changes to
kernfs in 4.2-rc1.