Re: [PATCH 2/2] livepatch: handle kzalloc failure

From: Petr Mladek
Date: Thu Dec 13 2018 - 07:33:11 EST


On Thu 2018-12-13 12:09:50, Nicholas Mc Guire wrote:
> kzalloc() return should be checked. On dummy_alloc() failing
> in kzalloc() NULL should be returned.
>
> Signed-off-by: Nicholas Mc Guire <hofrat@xxxxxxxxx>
> ---
>
> Problem was located with an experimental coccinelle script
>
> Patch was compile tested with: x86_64_defconfig + FTRACE=y
> FUNCTION_TRACER=y, EXPERT=y, LATENCYTOP=y, SAMPLES=y, SAMPLE_LIVEPATCH=y
> (with a number of unrelated sparse warnings on symbols not being static)
>
> Patch is against 4.20-rc6 (localversion-next is next-20181213)
>
> samples/livepatch/livepatch-shadow-mod.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/samples/livepatch/livepatch-shadow-mod.c b/samples/livepatch/livepatch-shadow-mod.c
> index 4c54b25..57d5cde 100644
> --- a/samples/livepatch/livepatch-shadow-mod.c
> +++ b/samples/livepatch/livepatch-shadow-mod.c
> @@ -118,6 +118,8 @@ noinline struct dummy *dummy_alloc(void)
>
> /* Oops, forgot to save leak! */
> leak = kzalloc(sizeof(int), GFP_KERNEL);
> + if (!leak)
> + return NULL;

The same comments apply here as for PATCH 1/2.

Best Regards,
Petr