net/mlx5: DR, prevent potential error pointer dereference

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: net/mlx5: DR, prevent potential error pointer dereference 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().

References

• https://git.kernel.org/stable/c/61f720e801443d4e2a3c0261eda4ad8431458dca
• https://git.kernel.org/stable/c/325cf73a1b449fea3158ab99d03a7a717aad1618
• https://git.kernel.org/stable/c/a59c61a1869ceefc65ef02886f91e8cd0062211f
• https://git.kernel.org/stable/c/11776cff0b563c8b8a4fa76cab620bfb633a8cb8