[dpdk-dev] [PATCH] net/bonding: fix buf corruption in merging un-transmitted packets

[Chas Williams]

On Fri, Aug 17, 2018 at 9:46 PM Jia Yu <jyu at vmware.com> wrote:

> When bond slave devices cannot transmit all packets in bufs array,
> tx_burst callback shall merge the un-transmitted packets back to
> bufs array. Recent merge logic introduced a bug which causes
> invalid mbuf addresses being written to bufs array.
>

Can you expand on this a bit?  What was the commit?



> When caller frees the un-transmitted packets, due to invalid addresses,
> application will crash.
>
> The fix is avoid shifting mbufs, and directly write un-transmitted
> packets back to bufs array.
>
> Signed-off-by: Jia Yu <jyu at vmware.com>
> ---
>  drivers/net/bonding/rte_eth_bond_pmd.c | 98
> +++++-----------------------------
>  1 file changed, 14 insertions(+), 84 deletions(-)
>
> diff --git a/drivers/net/bonding/rte_eth_bond_pmd.c
> b/drivers/net/bonding/rte_eth_bond_pmd.c
> index 58f7377..cce973a 100644
> --- a/drivers/net/bonding/rte_eth_bond_pmd.c
> +++ b/drivers/net/bonding/rte_eth_bond_pmd.c
> @@ -303,7 +303,7 @@ bond_ethdev_tx_burst_8023ad_fast_queue(void *queue,
> struct rte_mbuf **bufs,
>         uint16_t slave_tx_count, slave_tx_fail_count[RTE_MAX_ETHPORTS] = {
> 0 };
>         uint16_t total_tx_count = 0, total_tx_fail_count = 0;
>
> -       uint16_t i, j;
> +       uint16_t i;
>
>         if (unlikely(nb_bufs == 0))
>                 return 0;
> @@ -361,31 +361,9 @@ bond_ethdev_tx_burst_8023ad_fast_queue(void *queue,
> struct rte_mbuf **bufs,
>                         slave_tx_fail_count[i] = slave_nb_bufs[i] -
>                                         slave_tx_count;
>                         total_tx_fail_count += slave_tx_fail_count[i];
> -
> -                       /*
> -                        * Shift bufs to beginning of array to allow
> reordering
> -                        * later
> -                        */
> -                       for (j = 0; j < slave_tx_fail_count[i]; j++) {
> -                               slave_bufs[i][j] =
> -                                       slave_bufs[i][(slave_tx_count - 1)
> + j];
> -                       }
> -               }
> -       }
> -
> -       /*
> -        * If there are tx burst failures we move packets to end of bufs to
> -        * preserve expected PMD behaviour of all failed transmitted being
> -        * at the end of the input mbuf array
> -        */
> -       if (unlikely(total_tx_fail_count > 0)) {
> -               int bufs_idx = nb_bufs - total_tx_fail_count - 1;
> -
> -               for (i = 0; i < slave_count; i++) {
> -                       if (slave_tx_fail_count[i] > 0) {
> -                               for (j = 0; j < slave_tx_fail_count[i];
> j++)
> -                                       bufs[bufs_idx++] =
> slave_bufs[i][j];
> -                       }
> +                       memcpy(&bufs[nb_bufs - total_tx_fail_count],
> +                              &slave_bufs[i][slave_tx_count],
> +                              slave_tx_fail_count[i] * sizeof(bufs[0]));
>                 }
>         }
>
> @@ -715,8 +693,8 @@ bond_ethdev_tx_burst_round_robin(void *queue, struct
> rte_mbuf **bufs,
>                                 tx_fail_total += tx_fail_slave;
>
>                                 memcpy(&bufs[nb_pkts - tx_fail_total],
> -
>  &slave_bufs[i][num_tx_slave],
> -                                               tx_fail_slave *
> sizeof(bufs[0]));
> +                                      &slave_bufs[i][num_tx_slave],
> +                                      tx_fail_slave * sizeof(bufs[0]));
>                         }
>                         num_tx_total += num_tx_slave;
>                 }
> @@ -1224,7 +1202,7 @@ bond_ethdev_tx_burst_balance(void *queue, struct
> rte_mbuf **bufs,
>         uint16_t slave_tx_count, slave_tx_fail_count[RTE_MAX_ETHPORTS] = {
> 0 };
>         uint16_t total_tx_count = 0, total_tx_fail_count = 0;
>
> -       uint16_t i, j;
> +       uint16_t i;
>
>         if (unlikely(nb_bufs == 0))
>                 return 0;
> @@ -1268,31 +1246,9 @@ bond_ethdev_tx_burst_balance(void *queue, struct
> rte_mbuf **bufs,
>                         slave_tx_fail_count[i] = slave_nb_bufs[i] -
>                                         slave_tx_count;
>                         total_tx_fail_count += slave_tx_fail_count[i];
> -
> -                       /*
> -                        * Shift bufs to beginning of array to allow
> reordering
> -                        * later
> -                        */
> -                       for (j = 0; j < slave_tx_fail_count[i]; j++) {
> -                               slave_bufs[i][j] =
> -                                       slave_bufs[i][(slave_tx_count - 1)
> + j];
> -                       }
> -               }
> -       }
> -
> -       /*
> -        * If there are tx burst failures we move packets to end of bufs to
> -        * preserve expected PMD behaviour of all failed transmitted being
> -        * at the end of the input mbuf array
> -        */
> -       if (unlikely(total_tx_fail_count > 0)) {
> -               int bufs_idx = nb_bufs - total_tx_fail_count - 1;
> -
> -               for (i = 0; i < slave_count; i++) {
> -                       if (slave_tx_fail_count[i] > 0) {
> -                               for (j = 0; j < slave_tx_fail_count[i];
> j++)
> -                                       bufs[bufs_idx++] =
> slave_bufs[i][j];
> -                       }
> +                       memcpy(&bufs[nb_bufs - total_tx_fail_count],
> +                              &slave_bufs[i][slave_tx_count],
> +                              slave_tx_fail_count[i] * sizeof(bufs[0]));
>                 }
>         }
>
> @@ -1322,7 +1278,7 @@ bond_ethdev_tx_burst_8023ad(void *queue, struct
> rte_mbuf **bufs,
>         uint16_t slave_tx_count, slave_tx_fail_count[RTE_MAX_ETHPORTS] = {
> 0 };
>         uint16_t total_tx_count = 0, total_tx_fail_count = 0;
>
> -       uint16_t i, j;
> +       uint16_t i;
>
>         if (unlikely(nb_bufs == 0))
>                 return 0;
> @@ -1384,35 +1340,9 @@ bond_ethdev_tx_burst_8023ad(void *queue, struct
> rte_mbuf **bufs,
>                                                 slave_tx_count;
>                                 total_tx_fail_count +=
> slave_tx_fail_count[i];
>
> -                               /*
> -                                * Shift bufs to beginning of array to
> allow
> -                                * reordering later
> -                                */
> -                               for (j = 0; j < slave_tx_fail_count[i];
> j++)
> -                                       slave_bufs[i][j] =
> -                                               slave_bufs[i]
> -                                                       [(slave_tx_count -
> 1)
> -                                                       + j];
> -                       }
> -               }
> -
> -               /*
> -                * If there are tx burst failures we move packets to end of
> -                * bufs to preserve expected PMD behaviour of all failed
> -                * transmitted being at the end of the input mbuf array
> -                */
> -               if (unlikely(total_tx_fail_count > 0)) {
> -                       int bufs_idx = nb_bufs - total_tx_fail_count - 1;
> -
> -                       for (i = 0; i < slave_count; i++) {
> -                               if (slave_tx_fail_count[i] > 0) {
> -                                       for (j = 0;
> -                                               j < slave_tx_fail_count[i];
> -                                               j++) {
> -                                               bufs[bufs_idx++] =
> -                                                       slave_bufs[i][j];
> -                                       }
> -                               }
> +                               memcpy(&bufs[nb_bufs -
> total_tx_fail_count],
> +                                      &slave_bufs[i][slave_tx_count],
> +                                      slave_tx_fail_count[i] *
> sizeof(bufs[0]));
>                         }
>                 }
>         }
> --
> 2.7.4
>
>