From: Nikolay Aleksandrov nikolay@nvidia.com
[ Upstream commit 8837cbbf854246f5f4d565f21e6baa945d37aded ]
We need a way to release a fib6_nh's per-cpu dsts when replacing nexthops otherwise we can end up with stale per-cpu dsts which hold net device references, so add a new IPv6 stub called fib6_nh_release_dsts. It must be used after an RCU grace period, so no new dsts can be created through a group's nexthop entry. Similar to fib6_nh_release it shouldn't be used if fib6_nh_init has failed so it doesn't need a dummy stub when IPv6 is not enabled.
Fixes: 7bf4796dd099 ("nexthops: add support for replace") Signed-off-by: Nikolay Aleksandrov nikolay@nvidia.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- include/net/ip6_fib.h | 1 + include/net/ipv6_stubs.h | 1 + net/ipv6/af_inet6.c | 1 + net/ipv6/route.c | 19 +++++++++++++++++++ 4 files changed, 22 insertions(+)
diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h index ac5ff3c3afb14..88bc66b8d02b0 100644 --- a/include/net/ip6_fib.h +++ b/include/net/ip6_fib.h @@ -491,6 +491,7 @@ int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh, struct fib6_config *cfg, gfp_t gfp_flags, struct netlink_ext_ack *extack); void fib6_nh_release(struct fib6_nh *fib6_nh); +void fib6_nh_release_dsts(struct fib6_nh *fib6_nh);
int call_fib6_entry_notifiers(struct net *net, enum fib_event_type event_type, diff --git a/include/net/ipv6_stubs.h b/include/net/ipv6_stubs.h index 8fce558b5fea3..14a43111ffc6a 100644 --- a/include/net/ipv6_stubs.h +++ b/include/net/ipv6_stubs.h @@ -47,6 +47,7 @@ struct ipv6_stub { struct fib6_config *cfg, gfp_t gfp_flags, struct netlink_ext_ack *extack); void (*fib6_nh_release)(struct fib6_nh *fib6_nh); + void (*fib6_nh_release_dsts)(struct fib6_nh *fib6_nh); void (*fib6_update_sernum)(struct net *net, struct fib6_info *rt); int (*ip6_del_rt)(struct net *net, struct fib6_info *rt, bool skip_notify); void (*fib6_rt_update)(struct net *net, struct fib6_info *rt, diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c index e648fbebb1670..090575346daf6 100644 --- a/net/ipv6/af_inet6.c +++ b/net/ipv6/af_inet6.c @@ -1016,6 +1016,7 @@ static const struct ipv6_stub ipv6_stub_impl = { .ip6_mtu_from_fib6 = ip6_mtu_from_fib6, .fib6_nh_init = fib6_nh_init, .fib6_nh_release = fib6_nh_release, + .fib6_nh_release_dsts = fib6_nh_release_dsts, .fib6_update_sernum = fib6_update_sernum_stub, .fib6_rt_update = fib6_rt_update, .ip6_del_rt = ip6_del_rt, diff --git a/net/ipv6/route.c b/net/ipv6/route.c index a68a7d7c07280..6fef0d7586bf6 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -3570,6 +3570,25 @@ void fib6_nh_release(struct fib6_nh *fib6_nh) fib_nh_common_release(&fib6_nh->nh_common); }
+void fib6_nh_release_dsts(struct fib6_nh *fib6_nh) +{ + int cpu; + + if (!fib6_nh->rt6i_pcpu) + return; + + for_each_possible_cpu(cpu) { + struct rt6_info *pcpu_rt, **ppcpu_rt; + + ppcpu_rt = per_cpu_ptr(fib6_nh->rt6i_pcpu, cpu); + pcpu_rt = xchg(ppcpu_rt, NULL); + if (pcpu_rt) { + dst_dev_put(&pcpu_rt->dst); + dst_release(&pcpu_rt->dst); + } + } +} + static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg, gfp_t gfp_flags, struct netlink_ext_ack *extack)