From: Nikolay Aleksandrov <razor@blackwall.org>
To: netdev@vger.kernel.org
Cc: idosch@nvidia.com, davem@davemloft.net, edumazet@google.com,
kuba@kernel.org, pabeni@redhat.com, horms@kernel.org,
roopa@nvidia.com, bridge@lists.linux.dev, andrew+netdev@lunn.ch,
dlstevens@us.ibm.com, amwang@redhat.com,
Nikolay Aleksandrov <razor@blackwall.org>
Subject: [PATCH net 0/2] bridge/vxlan: fix reading neigh ha without synchronization
Date: Mon, 17 Aug 2026 17:36:11 +0300 [thread overview]
Message-ID: <20260817143613.685769-1-razor@blackwall.org> (raw)
Hi,
Neigh ha address must be read using the seqlock to get a stable snapshot.
Both the bridge and vxlan read it directly and can see partial updates.
I reproduced both issues with running neigh updates and exercising these
paths in parallel and saw partial addresses, e.g. updating between
neigh A: 02:00:00:00:00:00 neigh B: fe:ff:ff:ff:ff:ff was able to observe
02:00:ff:ff:ff:ff and fe:ff:00:00:00:00 in packets. Noticed this initially
in the bridge, then checked vxlan and its arp/neigh_reduce functions have
the same bug, route_shortcircuit is doing the right thing already.
Cheers,
Nik
Nikolay Aleksandrov (2):
net: bridge: arp/nd proxy: fix reading neigh ha
vxlan: fix reading neigh ha
drivers/net/vxlan/vxlan_core.c | 20 +++++++++++++-------
net/bridge/br_arp_nd_proxy.c | 24 ++++++++++++++----------
2 files changed, 27 insertions(+), 17 deletions(-)
--
2.47.3
next reply other threads:[~2026-08-17 14:36 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-17 14:36 Nikolay Aleksandrov [this message]
2026-08-17 14:36 ` [PATCH net 1/2] net: bridge: arp/nd proxy: fix reading neigh ha Nikolay Aleksandrov
2026-08-17 14:36 ` [PATCH net 2/2] vxlan: " Nikolay Aleksandrov
2026-08-17 15:25 ` [PATCH net 0/2] bridge/vxlan: fix reading neigh ha without synchronization Nikolay Aleksandrov
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