ovpn: replace bind when clearing stale local source

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The UDP output fallback clears bind->local in place when the remembered
source address is no longer usable. The bind is RCU-published and read
locklessly by concurrent TX, so an IPv6 reader can observe a torn
address.

Retry the route lookup with source address autoselection without
modifying the bind. After a successful lookup, revalidate the bind and
route key under peer->lock, reset the dst cache, and best-effort publish
a replacement bind with a wildcard local address.

Do not cache the resolved dst when clearing the local source. Replacing
the source invalidates all per-CPU cache entries, while
dst_cache_set_ip4 and dst_cache_set_ip6 update only the current CPU
slot. The current packet can still use the resolved route; if bind
allocation fails, a later cache miss retries the repair.

Fixes: 08857b5ec5 ("ovpn: implement basic TX path (UDP)")
Signed-off-by: Ralf Lici <ralf@mandelbit.com>
Signed-off-by: Antonio Quartulli <antonio@openvpn.net>

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Ralf Lici 2026-08-28 16:50:27 +02:00 • committed by Antonio Quartulli

parent aea934a221

commit 7d8104988f

1 changed files with 56 additions and 25 deletions

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drivers/net/ovpn/udp.c

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