[v2,1/2] net/af_xdp: fix use after free in af_xdp_tx_zc()
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Commit Message
tx_bytes is computed after both legs are tested. This might
produce a use after memory free.
The computation is now moved into each leg.
Bugzilla ID: 1440
Fixes: d8a210774e1d ("net/af_xdp: support unaligned umem chunks")
Signed-off-by: Ariel Otilibili <ariel.otilibili@6wind.com>
---
drivers/net/af_xdp/rte_eth_af_xdp.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
Comments
On 16/01/2025 17:51, Ariel Otilibili wrote:
> tx_bytes is computed after both legs are tested. This might
> produce a use after memory free.
>
> The computation is now moved into each leg.
>
> Bugzilla ID: 1440
> Fixes: d8a210774e1d ("net/af_xdp: support unaligned umem chunks")
> Signed-off-by: Ariel Otilibili <ariel.otilibili@6wind.com>
> ---
> drivers/net/af_xdp/rte_eth_af_xdp.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c b/drivers/net/af_xdp/rte_eth_af_xdp.c
> index 814398ba4b44..4326a29f7042 100644
> --- a/drivers/net/af_xdp/rte_eth_af_xdp.c
> +++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
> @@ -574,6 +574,7 @@ af_xdp_tx_zc(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
> umem->mb_pool->header_size;
> offset = offset << XSK_UNALIGNED_BUF_OFFSET_SHIFT;
> desc->addr = addr | offset;
> + tx_bytes += mbuf->pkt_len;
> count++;
> } else {
> struct rte_mbuf *local_mbuf =
> @@ -601,11 +602,10 @@ af_xdp_tx_zc(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
> desc->addr = addr | offset;
> rte_memcpy(pkt, rte_pktmbuf_mtod(mbuf, void *),
> desc->len);
> + tx_bytes += mbuf->pkt_len;
> rte_pktmbuf_free(mbuf);
> count++;
> }
> -
> - tx_bytes += mbuf->pkt_len;
> }
>
> out:
I think that you could've just set tx_bytes to the desc->len as this is
being set in all scenarios...
tx_bytes += desc->len;
Hi Maryam,
On Mon, Jan 20, 2025 at 3:54 PM Maryam Tahhan <mtahhan@redhat.com> wrote:
> I think that you could've just set tx_bytes to the desc->len as this is
> being set in all scenarios...
>
> tx_bytes += desc->len;
>
Thanks for your feedback. I'll change that.
@@ -574,6 +574,7 @@ af_xdp_tx_zc(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
umem->mb_pool->header_size;
offset = offset << XSK_UNALIGNED_BUF_OFFSET_SHIFT;
desc->addr = addr | offset;
+ tx_bytes += mbuf->pkt_len;
count++;
} else {
struct rte_mbuf *local_mbuf =
@@ -601,11 +602,10 @@ af_xdp_tx_zc(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
desc->addr = addr | offset;
rte_memcpy(pkt, rte_pktmbuf_mtod(mbuf, void *),
desc->len);
+ tx_bytes += mbuf->pkt_len;
rte_pktmbuf_free(mbuf);
count++;
}
-
- tx_bytes += mbuf->pkt_len;
}
out: