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SubjectRe: [PATCH 2/2 V2] livepatch: handle kzalloc failure properly
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On 12/13/2018 09:05 AM, 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@osadl.org>
> ---
>
> Problem was located with an experimental coccinelle script
>
> V2: returning NULL is ok but not without cleanup - thanks to
> Petr Mladek <pmladek@suse.com> for catching this.
>
> 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 | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/samples/livepatch/livepatch-shadow-mod.c b/samples/livepatch/livepatch-shadow-mod.c
> index 4c54b25..4aa8a88 100644
> --- a/samples/livepatch/livepatch-shadow-mod.c
> +++ b/samples/livepatch/livepatch-shadow-mod.c
> @@ -118,6 +118,10 @@ noinline struct dummy *dummy_alloc(void)
>
> /* Oops, forgot to save leak! */
> leak = kzalloc(sizeof(int), GFP_KERNEL);
> + if (!leak) {
> + kfree(d);
> + return NULL;
> + }
>
> pr_info("%s: dummy @ %p, expires @ %lx\n",
> __func__, d, d->jiffies_expire);
>

Hi Nicholas,

Thanks for finding and fixing these up... can we either squash these two
patches into a single commit or give them unique subject lines? Code
looks good (including Petr's suggested fix) otherwise.

-- Joe

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