diff options
| author | Kuniyuki Iwashima <kuniyu@google.com> | 2026-06-04 22:46:23 +0000 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-06-08 17:06:23 -0700 |
| commit | 76ea2ba2297e0bbd9ddecc971edff93039def6f2 (patch) | |
| tree | a2bcb3f4c340b20483a1a5aa8d865e35490b4025 | |
| parent | c2f5fd21aca4c7d002bbf264da4464509674ee78 (diff) | |
ip6mr: Convert ip6mr_rtm_getroute() to RCU.
ip6mr_rtm_getroute() calls __ip6mr_get_table(), ip6mr_cache_find(),
and ip6mr_fill_mroute().
Once created, struct mr_table is not freed until netns dismantle,
so it's safe under RCU.
ip6mr_cache_find() iterates mrt->mfc_hash with rhl_for_each_entry_rcu().
struct mr_mfc is freed with call_rcu(), so this is also safe under
RCU.
ip6mr_fill_mroute() calls mr_fill_mroute(), which properly uses
RCU helpers.
Let's call them under RCU and register ip6mr_rtm_getroute() with
RTNL_FLAG_DOIT_UNLOCKED.
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260604224712.3209821-6-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | net/ipv6/ip6mr.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c index 018985593b03..51ba22f59506 100644 --- a/net/ipv6/ip6mr.c +++ b/net/ipv6/ip6mr.c @@ -1386,7 +1386,8 @@ static struct pernet_operations ip6mr_net_ops = { static const struct rtnl_msg_handler ip6mr_rtnl_msg_handlers[] __initconst_or_module = { {.owner = THIS_MODULE, .protocol = RTNL_FAMILY_IP6MR, .msgtype = RTM_GETROUTE, - .doit = ip6mr_rtm_getroute, .dumpit = ip6mr_rtm_dumproute}, + .doit = ip6mr_rtm_getroute, .dumpit = ip6mr_rtm_dumproute, + .flags = RTNL_FLAG_DOIT_UNLOCKED}, }; int __init ip6_mr_init(void) @@ -2710,6 +2711,8 @@ static int ip6mr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, grp = nla_get_in6_addr(tb[RTA_DST]); tableid = nla_get_u32_default(tb[RTA_TABLE], 0); + rcu_read_lock(); + mrt = __ip6mr_get_table(net, tableid ?: RT_TABLE_DEFAULT); if (!mrt) { NL_SET_ERR_MSG_MOD(extack, "MR table does not exist"); @@ -2717,10 +2720,7 @@ static int ip6mr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, goto err; } - /* entries are added/deleted only under RTNL */ - rcu_read_lock(); cache = ip6mr_cache_find(mrt, &src, &grp); - rcu_read_unlock(); if (!cache) { NL_SET_ERR_MSG_MOD(extack, "MR cache entry not found"); err = -ENOENT; @@ -2732,9 +2732,12 @@ static int ip6mr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, if (err < 0) goto err; + rcu_read_unlock(); + return rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); err: + rcu_read_unlock(); kfree_skb(skb); return err; } |