Re: [PATCH net] netdev: prevent accessing NAPI instances from another namespace

[Joe Damato <jdamato@fastly.com>]

On Mon, Jan 06, 2025 at 10:01:36AM -0800, Jakub Kicinski wrote:
> The NAPI IDs were not fully exposed to user space prior to the netlink
> API, so they were never namespaced. The netlink API must ensure that
> at the very least NAPI instance belongs to the same netns as the owner
> of the genl sock.
> 
> napi_by_id() can become static now, but it needs to move because of
> dev_get_by_napi_id().
> 
> Cc: stable@vger.kernel.org
> Fixes: 1287c1ae0fc2 ("netdev-genl: Support setting per-NAPI config values")
> Fixes: 27f91aaf49b3 ("netdev-genl: Add netlink framework functions for napi")
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
> ---
> Splitting this into fix per-version is a bit tricky, because we need
> to replace the napi_by_id() helper with a better one. I'll send the
> stable versions manually.
> 
> CC: jdamato@fastly.com
> CC: almasrymina@google.com
> CC: amritha.nambiar@intel.com
> CC: sridhar.samudrala@intel.com
> ---
>  net/core/dev.c         | 43 +++++++++++++++++++++++++++++-------------
>  net/core/dev.h         |  3 ++-
>  net/core/netdev-genl.c |  6 ++----
>  3 files changed, 34 insertions(+), 18 deletions(-)

Thanks.

Reviewed-by: Joe Damato <jdamato@fastly.com>