From 4be7b99c253f0c85a255cc1db7127ba3232dfa30 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Fri, 20 Mar 2026 07:23:00 +0000 Subject: ipv6: Don't remove permanent routes with exceptions from tb6_gc_hlist. The cited commit mechanically put fib6_remove_gc_list() just after every fib6_clean_expires() call. When a temporary route is promoted to a permanent route, there may already be exception routes tied to it. If fib6_remove_gc_list() removes the route from tb6_gc_hlist, such exception routes will no longer be aged. Let's replace fib6_remove_gc_list() with a new helper fib6_may_remove_gc_list() and use fib6_age_exceptions() there. Note that net->ipv6 is only compiled when CONFIG_IPV6 is enabled, so fib6_{add,remove,may_remove}_gc_list() are guarded. Fixes: 5eb902b8e719 ("net/ipv6: Remove expired routes with a separated list of routes.") Signed-off-by: Kuniyuki Iwashima Reviewed-by: David Ahern Link: https://patch.msgid.link/20260320072317.2561779-3-kuniyu@google.com Signed-off-by: Jakub Kicinski --- include/net/ip6_fib.h | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) (limited to 'include/net') diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h index 88b0dd4d8e09..9f8b6814a96a 100644 --- a/include/net/ip6_fib.h +++ b/include/net/ip6_fib.h @@ -507,12 +507,14 @@ void fib6_rt_update(struct net *net, struct fib6_info *rt, void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info, unsigned int flags); +void fib6_age_exceptions(struct fib6_info *rt, struct fib6_gc_args *gc_args, + unsigned long now); void fib6_run_gc(unsigned long expires, struct net *net, bool force); - void fib6_gc_cleanup(void); int fib6_init(void); +#if IS_ENABLED(CONFIG_IPV6) /* Add the route to the gc list if it is not already there * * The callers should hold f6i->fib6_table->tb6_lock. @@ -545,6 +547,23 @@ static inline void fib6_remove_gc_list(struct fib6_info *f6i) hlist_del_init(&f6i->gc_link); } +static inline void fib6_may_remove_gc_list(struct net *net, + struct fib6_info *f6i) +{ + struct fib6_gc_args gc_args; + + if (hlist_unhashed(&f6i->gc_link)) + return; + + gc_args.timeout = READ_ONCE(net->ipv6.sysctl.ip6_rt_gc_interval); + gc_args.more = 0; + + rcu_read_lock(); + fib6_age_exceptions(f6i, &gc_args, jiffies); + rcu_read_unlock(); +} +#endif + struct ipv6_route_iter { struct seq_net_private p; struct fib6_walker w; -- cgit v1.2.3