Re: [dpdk-dev] [PATCH 1/3] mbuf: add sanity checks on segment metadata

[Yongseok Koh <yskoh@mellanox.com>]

> On Sep 9, 2018, at 10:45 PM, David Marchand <david.marchand@6wind.com> wrote:
> 
> Add some basic checks on the segments offset and length metadata:
> always funny to have a < 0 tailroom cast to uint16_t ;-).
> 
> Signed-off-by: David Marchand <david.marchand@6wind.com>
> ---
> lib/librte_mbuf/rte_mbuf.c | 5 +++++
> 1 file changed, 5 insertions(+)
> 
> diff --git a/lib/librte_mbuf/rte_mbuf.c b/lib/librte_mbuf/rte_mbuf.c
> index e714c5a59..137a320ed 100644
> --- a/lib/librte_mbuf/rte_mbuf.c
> +++ b/lib/librte_mbuf/rte_mbuf.c
> @@ -200,6 +200,11 @@ rte_mbuf_sanity_check(const struct rte_mbuf *m, int is_header)
> 	pkt_len = m->pkt_len;
> 
> 	do {
> +		if (m->data_off > m->buf_len)
> +			rte_panic("data offset too big in mbuf segment\n");
> +		if ((uint32_t)m->data_off + (uint32_t)m->data_len >
> +				(uint32_t)m->buf_len)

Casting to uint32_t is needed? All of the three fields are uint16_t and it would
anyway happen because of the integer promotion rule. Right?


Thanks,
Yongseok

> +			rte_panic("data length too big in mbuf segment\n");
> 		nb_segs -= 1;
> 		pkt_len -= m->data_len;
> 	} while ((m = m->next) != NULL);
> -- 
> 2.17.1
>