Re: [PATCH v2] selinux: check for address length in selinux_socket_bind()

[Paul Moore]

On Fri, Mar 10, 2017 at 7:01 AM, Paul Moore <paul@xxxxxxxxxxxxxx> wrote:
> On Thu, Mar 9, 2017 at 2:12 AM, David Miller <davem@xxxxxxxxxxxxx> wrote:
>> From: Alexander Potapenko <glider@xxxxxxxxxx>
>> Date: Mon,  6 Mar 2017 19:46:14 +0100
>>
>>> KMSAN (KernelMemorySanitizer, a new error detection tool) reports use of
>>> uninitialized memory in selinux_socket_bind():
>>  ...
>>> (the line numbers are relative to 4.8-rc6, but the bug persists upstream)
>>>
>>> , when I run the following program as root:
>>  ...
>>> (for different values of |size| other error reports are printed).
>>>
>>> This happens because bind() unconditionally copies |size| bytes of
>>> |addr| to the kernel, leaving the rest uninitialized. Then
>>> security_socket_bind() reads the IP address bytes, including the
>>> uninitialized ones, to determine the port, or e.g. pass them further to
>>> sel_netnode_find(), which uses them to calculate a hash.
>>>
>>> Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx>
>>
>> Are the SELINUX folks going to pick this up or should I?
>
> Yes, it's on my list of things to merge, I was just a bit distracted
> this week with yet another audit problem.  I'm going to start making
> my way through the patch backlog today.

Just merged into selinux/next, thanks.  My apologies for the delay.

-- 
paul moore
www.paul-moore.com