Re: [PATCH] ublk: enforce ublks_max only for unprivileged devices

[Ming Lei <ming.lei@redhat.com>]

On Fri, Feb 28, 2025 at 09:31:48PM -0700, Uday Shankar wrote:
> Commit 403ebc877832 ("ublk_drv: add module parameter of ublks_max for
> limiting max allowed ublk dev"), claimed ublks_max was added to prevent
> a DoS situation with an untrusted user creating too many ublk devices.
> If that's the case, ublks_max should only restrict the number of
> unprivileged ublk devices in the system. Enforce the limit only for
> unprivileged ublk devices, and rename variables accordingly. Leave the
> external-facing parameter name unchanged, since changing it may break
> systems which use it (but still update its documentation to reflect its
> new meaning).
> 
> As a result of this change, in a system where there are only normal
> (non-unprivileged) devices, the maximum number of such devices is
> increased to 1 << MINORBITS, or 1048576. That ought to be enough for
> anyone, right?
> 
> Signed-off-by: Uday Shankar <ushankar@purestorage.com>

Looks fine,

Reviewed-by: Ming Lei <ming.lei@redhat.com>


Thanks,
Ming