[PATCH for-next] RDMA/rxe - Respond to skb_clone failure in rxe_recv.c

[PATCH for-next] RDMA/rxe - Respond to skb_clone failure in rxe_recv.c

[Bob Pearson]

If skb_clone is unable to allocate memory for a new
sk_buff this is not detected by the current code.

Check for a NULL return and continue. This is similar to
other errors in this loop over QPs attached to the multicast address
and consistent with the unreliable UD transport.

Fixes: e7ec96fc7932f ("RDMA/rxe: Fix skb lifetime in rxe_rcv_mcast_pkt()")
Signed-off-by: Bob Pearson <rpearson@hpe.com>
---
 drivers/infiniband/sw/rxe/rxe_recv.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/infiniband/sw/rxe/rxe_recv.c b/drivers/infiniband/sw/rxe/rxe_recv.c
index 11f3daf20768..c9984a28eecc 100644
--- a/drivers/infiniband/sw/rxe/rxe_recv.c
+++ b/drivers/infiniband/sw/rxe/rxe_recv.c
@@ -271,6 +271,9 @@ static void rxe_rcv_mcast_pkt(struct rxe_dev *rxe, struct sk_buff *skb)
 		else
 			per_qp_skb = skb;
 
+		if (unlikely(!per_qp_skb))
+			continue;
+
 		per_qp_pkt = SKB_TO_PKT(per_qp_skb);
 		per_qp_pkt->qp = qp;
 		rxe_add_ref(qp);
-- 
2.25.1

Re: [PATCH for-next] RDMA/rxe - Respond to skb_clone failure in rxe_recv.c

[Zhu Yanjun]

On Wed, Oct 14, 2020 at 2:44 AM Bob Pearson <rpearsonhpe@gmail.com> wrote:
>
> If skb_clone is unable to allocate memory for a new
> sk_buff this is not detected by the current code.
>
> Check for a NULL return and continue. This is similar to
> other errors in this loop over QPs attached to the multicast address
> and consistent with the unreliable UD transport.
>
> Fixes: e7ec96fc7932f ("RDMA/rxe: Fix skb lifetime in rxe_rcv_mcast_pkt()")

Addresses-Coverity-ID: 1497804: Null pointer dereferences (NULL_RETURNS)

Thanks
Zhu Yanjun

> Signed-off-by: Bob Pearson <rpearson@hpe.com>
> ---
>  drivers/infiniband/sw/rxe/rxe_recv.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/drivers/infiniband/sw/rxe/rxe_recv.c b/drivers/infiniband/sw/rxe/rxe_recv.c
> index 11f3daf20768..c9984a28eecc 100644
> --- a/drivers/infiniband/sw/rxe/rxe_recv.c
> +++ b/drivers/infiniband/sw/rxe/rxe_recv.c
> @@ -271,6 +271,9 @@ static void rxe_rcv_mcast_pkt(struct rxe_dev *rxe, struct sk_buff *skb)
>                 else
>                         per_qp_skb = skb;
>
> +               if (unlikely(!per_qp_skb))
> +                       continue;
> +
>                 per_qp_pkt = SKB_TO_PKT(per_qp_skb);
>                 per_qp_pkt->qp = qp;
>                 rxe_add_ref(qp);
> --
> 2.25.1
>

Re: [PATCH for-next] RDMA/rxe - Respond to skb_clone failure in rxe_recv.c

[Jason Gunthorpe]

On Tue, Oct 13, 2020 at 01:42:37PM -0500, Bob Pearson wrote:
> If skb_clone is unable to allocate memory for a new
> sk_buff this is not detected by the current code.
> 
> Check for a NULL return and continue. This is similar to
> other errors in this loop over QPs attached to the multicast address
> and consistent with the unreliable UD transport.
> 
> Fixes: e7ec96fc7932f ("RDMA/rxe: Fix skb lifetime in rxe_rcv_mcast_pkt()")
> Signed-off-by: Bob Pearson <rpearson@hpe.com>
> ---
>  drivers/infiniband/sw/rxe/rxe_recv.c | 3 +++
>  1 file changed, 3 insertions(+)

Subject should be 'RDMA/rxe:' not '-'

Place () after function names for clarity

Flow text to the full 76 lines

I fixed it all up and applied to for-next

Thanks,
Jason