Re: [PATCH rdma-next] RDMA/cma: Initialize traffic_class to 0 for multicast path records

[Leon Romanovsky <leonro@nvidia.com>]

On Tue, Sep 26, 2023 at 10:25:41AM +0300, Mark Zhang wrote:
> Initialize traffic_class to 0 so that it wouldn't have a random value,
> which causes a random IP DSCP in RoCEv2.

It will be great to see call trace which explains how. I think that
ib.rec.sl has same issue.

diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index c343edf2f664..1e2cd7c8716e 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -4968,7 +4968,7 @@ static int cma_iboe_join_multicast(struct rdma_id_private *id_priv,
        int err = 0;
        struct sockaddr *addr = (struct sockaddr *)&mc->addr;
        struct net_device *ndev = NULL;
-       struct ib_sa_multicast ib;
+       struct ib_sa_multicast ib = {};
        enum ib_gid_type gid_type;
        bool send_only;

Thanks

> 
> Fixes: b5de0c60cc30 ("RDMA/cma: Fix use after free race in roce multicast join")
> Signed-off-by: Mark Zhang <markzhang@nvidia.com>
> ---
>  drivers/infiniband/core/cma.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
> index c343edf2f664..d3a72f4b9863 100644
> --- a/drivers/infiniband/core/cma.c
> +++ b/drivers/infiniband/core/cma.c
> @@ -4990,6 +4990,7 @@ static int cma_iboe_join_multicast(struct rdma_id_private *id_priv,
>  	ib.rec.rate = IB_RATE_PORT_CURRENT;
>  	ib.rec.hop_limit = 1;
>  	ib.rec.mtu = iboe_get_mtu(ndev->mtu);
> +	ib.rec.traffic_class = 0;
>  
>  	if (addr->sa_family == AF_INET) {
>  		if (gid_type == IB_GID_TYPE_ROCE_UDP_ENCAP) {
> -- 
> 2.37.1
>