net/mlx5: DR, prevent potential error pointer dereference

[ Upstream commit 11776cff0b563c8b8a4fa76cab620bfb633a8cb8 ]

The dr_domain_add_vport_cap() function generally returns NULL on error
but sometimes we want it to return ERR_PTR(-EBUSY) so the caller can
retry.  The problem here is that "ret" can be either -EBUSY or -ENOMEM
and if it's and -ENOMEM then the error pointer is propogated back and
eventually dereferenced in dr_ste_v0_build_src_gvmi_qpn_tag().

Fixes: 11a45def2e19 ("net/mlx5: DR, Add support for SF vports")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/07477254-e179-43e2-b1b3-3b9db4674195@stanley.mountain
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_domain.c b/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_domain.c
index fc6ae49b5ecce46eca0fa2317d184374a8f0735d..d462017c6a957323bd33c4bb567720d7f375272e 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_domain.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_domain.c
@@ -195,7 +195,9 @@ dr_domain_add_vport_cap(struct mlx5dr_domain *dmn, u16 vport)
        if (ret) {
                mlx5dr_dbg(dmn, "Couldn't insert new vport into xarray (%d)\n", ret);
                kvfree(vport_caps);
-               return ERR_PTR(ret);
+               if (ret == -EBUSY)
+                       return ERR_PTR(-EBUSY);
+               return NULL;
        }
 
        return vport_caps;