Re: [PATCH] kasan: call kasan_malloc() from __kmalloc_*track_caller()

[Hyeonggon Yoo]

On Tue, Sep 13, 2022 at 07:00:01PM -0700, Peter Collingbourne wrote:
> We were failing to call kasan_malloc() from __kmalloc_*track_caller()
> which was causing us to sometimes fail to produce KASAN error reports
> for allocations made using e.g. devm_kcalloc(), as the KASAN poison was
> not being initialized. Fix it.
> 
> Signed-off-by: Peter Collingbourne <pcc@xxxxxxxxxx>
> Cc: <stable@xxxxxxxxxxxxxxx> # 5.15
> ---
> The same problem is being fixed upstream in:
> https://lore.kernel.org/all/20220817101826.236819-6-42.hyeyoo@xxxxxxxxx/
> as part of a larger patch series, but this more targeted fix seems
> more suitable for the stable kernel. Hyeonggon, maybe you can add
> this patch to the start of your series and it can be picked up
> by the stable maintainers.
> 
>  mm/slub.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/mm/slub.c b/mm/slub.c
> index 862dbd9af4f5..875c569c5cbe 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -4926,6 +4926,8 @@ void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, unsigned long caller)
>  	/* Honor the call site pointer we received. */
>  	trace_kmalloc(caller, ret, s, size, s->size, gfpflags);
>  
> +	ret = kasan_kmalloc(s, ret, size, gfpflags);
> +
>  	return ret;
>  }
>  EXPORT_SYMBOL(__kmalloc_track_caller);
> @@ -4957,6 +4959,8 @@ void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags,
>  	/* Honor the call site pointer we received. */
>  	trace_kmalloc_node(caller, ret, s, size, s->size, gfpflags, node);
>  
> +	ret = kasan_kmalloc(s, ret, size, gfpflags);
> +
>  	return ret;
>  }
>  EXPORT_SYMBOL(__kmalloc_node_track_caller);
> -- 
> 2.37.2.789.g6183377224-goog
>

Ah, I should have sent it to stable team ;)

I think "Option 3" in Documentation/process/stable-kernel-rules.rst will be appropriate,
So will resend this after the series goes to Linus's tree.

Thank you Peter!

-- 
Thanks,
Hyeonggon