[PATCH] RDMA/uverbs: Consider capability of the process that opens the file

[Jason Gunthorpe]

On Thu, Mar 13, 2025 at 07:08:32AM +0200, Parav Pandit wrote:
> Currently, the capability check is done on the current process which
> may have the CAP_NET_RAW capability, but such process may not have
> opened the file. A file may could have been opened by a lesser
> privilege process that does not possess the CAP_NET_RAW capability.

> To avoid such situations, perform the capability checks against
> the file's credentials. This approach ensures that the capabilities
> of the process that opened the file are enforced.
> 
> Fixes: c938a616aadb ("IB/core: Add raw packet QP type")
> Signed-off-by: Parav Pandit <parav at nvidia.com>
> Suggested-by: Eric W. Biederman <ebiederm at xmission.com>
> 
> ---
> 
> Eric,
> 
> Shouldn't we check the capabilities of the process that opened the
> file and also the current process that is issuing the create_flow()
> ioctl? This way, the minimum capabilities of both processes are
> considered.

I would say no, that is not our model in RDMA. The process that opens
the file is irrelevant. We only check the current system call context
for capability, much like any other systemcall.

Jason