Re: [PATCH][next] powerpc/vas: Fix potential NULL pointer dereference

[Michael Ellerman]

"Gustavo A. R. Silva" <gustavoars@xxxxxxxxxx> writes:
> On Mon, Oct 18, 2021 at 02:09:31PM -0700, Tyrel Datwyler wrote:
>> On 10/14/21 10:03 PM, Gustavo A. R. Silva wrote:
>> > (!ptr && !ptr->foo) strikes again. :)
>> > 
>> > The expression (!ptr && !ptr->foo) is bogus and in case ptr is NULL,
>> > it leads to a NULL pointer dereference: ptr->foo.
>> > 
>> > Fix this by converting && to ||
>> > 
>> > This issue was detected with the help of Coccinelle, and audited and
>> > fixed manually.
>> > 
>> > Fixes: 1a0d0d5ed5e3 ("powerpc/vas: Add platform specific user window operations")
>> > Cc: stable@xxxxxxxxxxxxxxx
>> > Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
>> Looking at the usage pattern it is obvious that if we determine !ptr attempting
>> to also confirm !ptr->ops is going to blow up.
>> 
>> LGTM.
>> 
>> Reviewed-by: Tyrel Datwyler <tyreld@xxxxxxxxxxxxx>
>
> I think I'll take this in my tree.

I've already put it in powerpc/next:

  https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/commit/?h=next&id=61cb9ac66b30374c7fd8a8b2a3c4f8f432c72e36

If you need to pick it up as well for some reason that's fine.

cheers