Re: [PATCH] x86/microcode/AMD: fix read of uninitialized data

From: Dan Carpenter
Date: Tue Apr 10 2018 - 10:23:53 EST


On Tue, Apr 10, 2018 at 02:41:23PM +0100, Colin King wrote:
> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>
> Currently function __load_ucode_amd can assign an uninitialized cp to *ret
> if get_builtin_microcode returns false.

What are you looking at? Here is how it looks in linux-next:

270
271 if (!get_builtin_microcode(&cp, x86_family(cpuid_1_eax)))
272 cp = find_microcode_in_initrd(path, use_pa);
273


If get_builtin_microcode() returns false, then cp is initialized on the
next line.

Maybe the issue is that cp.name is uninitialized. It doesn't cause an
issue but it would be understandable for a static checker to warn about
it when we do "*ret = cp;".

regards,
dan carpenter