Re: [PATCH net 0/2] bridge: mcast: Fix MDB exhaustion by rejected entries

[Gabriel Goller <g.goller@proxmox.com>]

On 16.10.2026 13:14, Ido Schimmel wrote:
> When the bridge fails to create a port group for a new MDB entry, the
> entry is left behind with no ports and is never deleted, but it is still
> counted towards mcast_hash_max. Since the introduction of
> mcast_max_groups, a host behind a port that reached its maximum can use
> this to exhaust the MDB and disable multicast snooping.
> 
> Patch #1 fixes the problem by deleting the entry upon failure.
> 
> Patch #2 adds a selftest.
> 
> Ido Schimmel (2):
>   bridge: mcast: Delete empty MDB entry when port group creation fails
>   selftests: forwarding: bridge_mdb_max: Add a test for rejected MDB
>     entries
> 
>  net/bridge/br_mdb.c                           |  16 +-
>  net/bridge/br_multicast.c                     |   9 ++
>  net/bridge/br_private.h                       |   1 +
>  .../net/forwarding/bridge_mdb_max.sh          | 138 ++++++++++++++++++
>  4 files changed, 161 insertions(+), 3 deletions(-)
> 
> -- 
> 2.56.0

Thanks,
Consider:

Tested-by: Gabriel Goller <g.goller@proxmox.com>
Reviewed-by: Gabriel Goller <g.goller@proxmox.com>