RE: [PATCH net-next] lib: packing: catch kunit_kzalloc() failure in the pack() test

[Keller, Jacob E]

> -----Original Message-----
> From: Vladimir Oltean <vladimir.oltean@xxxxxxx>
> Sent: Friday, October 4, 2024 4:00 AM
> To: netdev@xxxxxxxxxxxxxxx
> Cc: David S. Miller <davem@xxxxxxxxxxxxx>; Eric Dumazet
> <edumazet@xxxxxxxxxx>; Jakub Kicinski <kuba@xxxxxxxxxx>; Paolo Abeni
> <pabeni@xxxxxxxxxx>; Keller, Jacob E <jacob.e.keller@xxxxxxxxx>; Kitszel,
> Przemyslaw <przemyslaw.kitszel@xxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx
> Subject: [PATCH net-next] lib: packing: catch kunit_kzalloc() failure in the pack()
> test
> 
> kunit_kzalloc() may fail. Other call sites verify that this is the case,
> either using a direct comparison with the NULL pointer, or the
> KUNIT_ASSERT_NOT_NULL() or KUNIT_ASSERT_NOT_ERR_OR_NULL().
> 
> Pick KUNIT_ASSERT_NOT_NULL() as the error handling method that made most
> sense to me. It's an unlikely thing to happen, but at least we call
> __kunit_abort() instead of dereferencing this NULL pointer.
> 
> Fixes: e9502ea6db8a ("lib: packing: add KUnit tests adapted from selftests")
> Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
> ---
>  lib/packing_test.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/lib/packing_test.c b/lib/packing_test.c
> index 015ad1180d23..b38ea43c03fd 100644
> --- a/lib/packing_test.c
> +++ b/lib/packing_test.c
> @@ -375,6 +375,7 @@ static void packing_test_pack(struct kunit *test)
>  	int err;
> 
>  	pbuf = kunit_kzalloc(test, params->pbuf_size, GFP_KERNEL);
> +	KUNIT_ASSERT_NOT_NULL(test, pbuf);
> 
>  	err = pack(pbuf, params->uval, params->start_bit, params->end_bit,
>  		   params->pbuf_size, params->quirks);
> --
> 2.43.0

Oh good catch! I guess I had assumed that kunit_kzalloc would itself detect and fail instead of continuing....