netdev - [PATCH net v2 0/2] net: bridge: fix two MST bugs

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Message-ID: <20251105111919.1499702-1-razor@blackwall.org>
Date: Wed,  5 Nov 2025 13:19:17 +0200
From: Nikolay Aleksandrov <razor@...ckwall.org>
To: netdev@...r.kernel.org
Cc: tobias@...dekranz.com,
	idosch@...dia.com,
	kuba@...nel.org,
	davem@...emloft.net,
	bridge@...ts.linux.dev,
	pabeni@...hat.com,
	edumazet@...gle.com,
	horms@...nel.org,
	petrm@...dia.com,
	Nikolay Aleksandrov <razor@...ckwall.org>
Subject: [PATCH net v2 0/2] net: bridge: fix two MST bugs

Hi,
Patch 01 fixes a race condition that exists between expired fdb deletion
and port deletion when MST is enabled. Learning can happen after the
port's state has been changed to disabled which could lead to that
port's memory being used after it's been freed. The issue was reported
by syzbot, more information in patch 01. Patch 02 fixes an issue with
MST's static key which Ido spotted, we can have multiple bridges with MST
and a single bridge can erroneously disable it for all.

v2: dropped the selftest as it is useless with the new fix
    patch 01 - new fix approach relying on port's vlan group
    patch 02 - new patch fixing an issue with MST's static key

Thanks,
 Nik

Nikolay Aleksandrov (2):
  net: bridge: fix use-after-free due to MST port state bypass
  net: bridge: fix MST static key usage

 net/bridge/br_forward.c |  2 +-
 net/bridge/br_if.c      |  1 +
 net/bridge/br_input.c   |  4 ++--
 net/bridge/br_mst.c     | 10 ++++++++--
 net/bridge/br_private.h | 13 ++++++++++---
 5 files changed, 22 insertions(+), 8 deletions(-)

-- 
2.51.0