Re: [PATCH v3 0/4] netlink: bridge: fix nf_bridge->physindev use after free

On Thu, Jan 11, 2024 at 11:06:36PM +0800, Pavel Tikhomirov wrote:

Code processing skb from neigh->arp_queue can access its
nf_bridge->physindev, which can already be freed, leading to crash.

So, as Florian suggests, we can put physinif on nf_bridge and peek into
the original device with dev_get_by_index_rcu(), so that we can be sure
that device is not freed under us.

This is a second attempt to fix this issue, first attempt:

"neighbour: purge nf_bridged skb from foreign device neigh"
https://lore.kernel.org/netdev/20240108085232.95437-1-ptikhomirov@virtuozzo.com/ (local)

I have applied this series to nf.git

I have added a Fixed: tag sufficiently old to the patch fix so it can
reach -stable at some point.

My understanding is that this problem has been always there for
br_netfilter.