[PATCH net] net: dst: block BH in ipip6_tunnel_xmit
From: yuan.gao <hidden>
Date: 2026-06-22 03:31:33
Also in:
lkml
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Similar to commit 1378817486d6 ("tipc: block BH before using dst_cache"),
the dst cache helper functions must be invoked with local BH disabled.
This ensures proper synchronization and fixes a potential race condition
on SMP systems.
Signed-off-by: yuan.gao <redacted>
---
net/ipv6/sit.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 201347b4e1274..2a63b346634e7 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c@@ -934,14 +934,20 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb, IPPROTO_IPV6, 0, dst, tiph->saddr, 0, 0, sock_net_uid(tunnel->net, NULL)); + local_bh_disable(); rt = dst_cache_get_ip4(&tunnel->dst_cache, &fl4.saddr); + local_bh_enable(); + if (!rt) { rt = ip_route_output_flow(tunnel->net, &fl4, NULL); if (IS_ERR(rt)) { DEV_STATS_INC(dev, tx_carrier_errors); goto tx_error_icmp; } + + local_bh_disable(); dst_cache_set_ip4(&tunnel->dst_cache, &rt->dst, fl4.saddr); + local_bh_enable(); } if (rt->rt_type != RTN_UNICAST && rt->rt_type != RTN_LOCAL) {
--
2.32.0