Re: [PATCH v2 07/11] malloc: check result of rte_fbarray_get

[Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>]

2022-11-21 17:32 (UTC-0500), okaya@kernel.org:
> From: Sinan Kaya <okaya@kernel.org>
> 
> In eal_memalloc_is_contig result of call to rte_fbarray_get
> is dereferenced here and may be null.
> 
> Signed-off-by: Sinan Kaya <okaya@kernel.org>
> ---
>  lib/eal/common/eal_common_memalloc.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/lib/eal/common/eal_common_memalloc.c b/lib/eal/common/eal_common_memalloc.c
> index ab04479c1c..24506f8447 100644
> --- a/lib/eal/common/eal_common_memalloc.c
> +++ b/lib/eal/common/eal_common_memalloc.c
> @@ -126,6 +126,9 @@ eal_memalloc_is_contig(const struct rte_memseg_list *msl, void *start,
>  
>  		/* skip first iteration */
>  		ms = rte_fbarray_get(&msl->memseg_arr, start_seg);
> +		if (ms == NULL)
> +			return false;
> +
>  		cur = ms->iova;
>  		expected = cur + pgsz;
>  
> @@ -137,7 +140,7 @@ eal_memalloc_is_contig(const struct rte_memseg_list *msl, void *start,
>  				cur_seg++, expected += pgsz) {
>  			ms = rte_fbarray_get(&msl->memseg_arr, cur_seg);
>  
> -			if (ms->iova != expected)
> +			if ((ms != NULL) && (ms->iova != expected))
>  				return false;
>  		}
>  	}

Invariant: "msl->memseg_arr" elements for existing memsegs are used.
RTE_ASSERT(rte_fbarray_is_used(&msl->memseg_arr, ...)) would be sufficient.