net/octeontx: fix invalid access to indirect buffers

  Issue has been observed where fields of indirect buffers are
accessed after being set free by the diver. Also fixing freeing
of direct buffers to correct aura.

Fixes: 5cbe184802aa ("net/octeontx: support fast mbuf free")
Cc: stable@dpdk.org

Signed-off-by: David George <david.george@sophos.com>
Signed-off-by: Harman Kalra <hkalra@marvell.com>
---
 drivers/net/octeontx/octeontx_rxtx.h | 69 ++++++++++++++++++----------
 1 file changed, 46 insertions(+), 23 deletions(-)
  

On Mon, Sep 20, 2021 at 8:19 PM Harman Kalra <hkalra@marvell.com> wrote:
>
> Issue has been observed where fields of indirect buffers are
> accessed after being set free by the diver. Also fixing freeing
> of direct buffers to correct aura.
>
> Fixes: 5cbe184802aa ("net/octeontx: support fast mbuf free")
> Cc: stable@dpdk.org
>
> Signed-off-by: David George <david.george@sophos.com>
> Signed-off-by: Harman Kalra <hkalra@marvell.com>

Acked-by: Jerin Jacob <jerinj@marvell.com>
Applied to dpdk-next-net-mrvl/for-next-net. Thanks


> ---
>  drivers/net/octeontx/octeontx_rxtx.h | 69 ++++++++++++++++++----------
>  1 file changed, 46 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/net/octeontx/octeontx_rxtx.h b/drivers/net/octeontx/octeontx_rxtx.h
> index 2ed28ea563..e0723ac26a 100644
> --- a/drivers/net/octeontx/octeontx_rxtx.h
> +++ b/drivers/net/octeontx/octeontx_rxtx.h
> @@ -161,7 +161,7 @@ ptype_table[PTYPE_SIZE][PTYPE_SIZE][PTYPE_SIZE] = {
>
>
>  static __rte_always_inline uint64_t
> -octeontx_pktmbuf_detach(struct rte_mbuf *m)
> +octeontx_pktmbuf_detach(struct rte_mbuf *m, struct rte_mbuf **m_tofree)
>  {
>         struct rte_mempool *mp = m->pool;
>         uint32_t mbuf_size, buf_len;
> @@ -171,6 +171,8 @@ octeontx_pktmbuf_detach(struct rte_mbuf *m)
>
>         /* Update refcount of direct mbuf */
>         md = rte_mbuf_from_indirect(m);
> +       /* The real data will be in the direct buffer, inform callers this */
> +       *m_tofree = md;
>         refcount = rte_mbuf_refcnt_update(md, -1);
>
>         priv_size = rte_pktmbuf_priv_size(mp);
> @@ -203,18 +205,18 @@ octeontx_pktmbuf_detach(struct rte_mbuf *m)
>  }
>
>  static __rte_always_inline uint64_t
> -octeontx_prefree_seg(struct rte_mbuf *m)
> +octeontx_prefree_seg(struct rte_mbuf *m, struct rte_mbuf **m_tofree)
>  {
>         if (likely(rte_mbuf_refcnt_read(m) == 1)) {
>                 if (!RTE_MBUF_DIRECT(m))
> -                       return octeontx_pktmbuf_detach(m);
> +                       return octeontx_pktmbuf_detach(m, m_tofree);
>
>                 m->next = NULL;
>                 m->nb_segs = 1;
>                 return 0;
>         } else if (rte_mbuf_refcnt_update(m, -1) == 0) {
>                 if (!RTE_MBUF_DIRECT(m))
> -                       return octeontx_pktmbuf_detach(m);
> +                       return octeontx_pktmbuf_detach(m, m_tofree);
>
>                 rte_mbuf_refcnt_set(m, 1);
>                 m->next = NULL;
> @@ -315,6 +317,14 @@ __octeontx_xmit_prepare(struct rte_mbuf *tx_pkt, uint64_t *cmd_buf,
>                         const uint16_t flag)
>  {
>         uint16_t gaura_id, nb_desc = 0;
> +       struct rte_mbuf *m_tofree;
> +       rte_iova_t iova;
> +       uint16_t data_len;
> +
> +       m_tofree = tx_pkt;
> +
> +       data_len = tx_pkt->data_len;
> +       iova = rte_mbuf_data_iova(tx_pkt);
>
>         /* Setup PKO_SEND_HDR_S */
>         cmd_buf[nb_desc++] = tx_pkt->data_len & 0xffff;
> @@ -329,22 +339,23 @@ __octeontx_xmit_prepare(struct rte_mbuf *tx_pkt, uint64_t *cmd_buf,
>          * not, as SG_DESC[I] and SEND_HDR[II] are clear.
>          */
>         if (flag & OCCTX_TX_OFFLOAD_MBUF_NOFF_F)
> -               cmd_buf[0] |= (octeontx_prefree_seg(tx_pkt) <<
> +               cmd_buf[0] |= (octeontx_prefree_seg(tx_pkt, &m_tofree) <<
>                                58);
>
>         /* Mark mempool object as "put" since it is freed by PKO */
>         if (!(cmd_buf[0] & (1ULL << 58)))
> -               __mempool_check_cookies(tx_pkt->pool, (void **)&tx_pkt,
> +               __mempool_check_cookies(m_tofree->pool, (void **)&m_tofree,
>                                         1, 0);
>         /* Get the gaura Id */
> -       gaura_id = octeontx_fpa_bufpool_gaura((uintptr_t)tx_pkt->pool->pool_id);
> +       gaura_id =
> +               octeontx_fpa_bufpool_gaura((uintptr_t)m_tofree->pool->pool_id);
>
>         /* Setup PKO_SEND_BUFLINK_S */
>         cmd_buf[nb_desc++] = PKO_SEND_BUFLINK_SUBDC |
>                 PKO_SEND_BUFLINK_LDTYPE(0x1ull) |
>                 PKO_SEND_BUFLINK_GAUAR((long)gaura_id) |
> -               tx_pkt->data_len;
> -       cmd_buf[nb_desc++] = rte_mbuf_data_iova(tx_pkt);
> +               data_len;
> +       cmd_buf[nb_desc++] = iova;
>
>         return nb_desc;
>  }
> @@ -355,7 +366,9 @@ __octeontx_xmit_mseg_prepare(struct rte_mbuf *tx_pkt, uint64_t *cmd_buf,
>  {
>         uint16_t nb_segs, nb_desc = 0;
>         uint16_t gaura_id, len = 0;
> -       struct rte_mbuf *m_next = NULL;
> +       struct rte_mbuf *m_next = NULL, *m_tofree;
> +       rte_iova_t iova;
> +       uint16_t data_len;
>
>         nb_segs = tx_pkt->nb_segs;
>         /* Setup PKO_SEND_HDR_S */
> @@ -369,40 +382,50 @@ __octeontx_xmit_mseg_prepare(struct rte_mbuf *tx_pkt, uint64_t *cmd_buf,
>
>         do {
>                 m_next = tx_pkt->next;
> -               /* To handle case where mbufs belong to diff pools, like
> -                * fragmentation
> +               /* Get TX parameters up front, octeontx_prefree_seg might change
> +                * them
>                  */
> -               gaura_id = octeontx_fpa_bufpool_gaura((uintptr_t)
> -                                                     tx_pkt->pool->pool_id);
> +               m_tofree = tx_pkt;
> +               data_len = tx_pkt->data_len;
> +               iova = rte_mbuf_data_iova(tx_pkt);
>
>                 /* Setup PKO_SEND_GATHER_S */
> -               cmd_buf[nb_desc] = PKO_SEND_GATHER_SUBDC                 |
> -                                  PKO_SEND_GATHER_LDTYPE(0x1ull)        |
> -                                  PKO_SEND_GATHER_GAUAR((long)gaura_id) |
> -                                  tx_pkt->data_len;
> +               cmd_buf[nb_desc] = 0;
>
>                 /* SG_DESC[I] bit controls if buffer is to be freed or
>                  * not, as SEND_HDR[DF] and SEND_HDR[II] are clear.
>                  */
>                 if (flag & OCCTX_TX_OFFLOAD_MBUF_NOFF_F) {
>                         cmd_buf[nb_desc] |=
> -                            (octeontx_prefree_seg(tx_pkt) << 57);
> +                               (octeontx_prefree_seg(tx_pkt, &m_tofree) << 57);
>                 }
>
> +               /* To handle case where mbufs belong to diff pools, like
> +                * fragmentation
> +                */
> +               gaura_id = octeontx_fpa_bufpool_gaura((uintptr_t)
> +                                       m_tofree->pool->pool_id);
> +
> +               /* Setup PKO_SEND_GATHER_S */
> +               cmd_buf[nb_desc] |= PKO_SEND_GATHER_SUBDC                |
> +                                  PKO_SEND_GATHER_LDTYPE(0x1ull)        |
> +                                  PKO_SEND_GATHER_GAUAR((long)gaura_id) |
> +                                  data_len;
> +
>                 /* Mark mempool object as "put" since it is freed by
>                  * PKO.
>                  */
>                 if (!(cmd_buf[nb_desc] & (1ULL << 57))) {
>                         tx_pkt->next = NULL;
> -                       __mempool_check_cookies(tx_pkt->pool,
> -                                               (void **)&tx_pkt, 1, 0);
> +                       __mempool_check_cookies(m_tofree->pool,
> +                                               (void **)&m_tofree, 1, 0);
>                 }
>                 nb_desc++;
>
> -               cmd_buf[nb_desc++] = rte_mbuf_data_iova(tx_pkt);
> +               cmd_buf[nb_desc++] = iova;
>
>                 nb_segs--;
> -               len += tx_pkt->data_len;
> +               len += data_len;
>                 tx_pkt = m_next;
>         } while (nb_segs);
>
> --
> 2.18.0
>