[PATCH net v6 09/10] ip6mr: Lock RCU before ip6mr_get_table() call in ip6mr_rtm_getroute()
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STALE731d
From: Stefan Wiehler <hidden>
Date: 2024-10-17 17:42:23
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Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
Revision v6 of 2 in this series.
Revisions (2)
- v5 [diff vs current]
- v6 current
When IPV6_MROUTE_MULTIPLE_TABLES is enabled, multicast routing tables
must be read under RCU or RTNL lock.
Fixes: d1db275dd3f6 ("ipv6: ip6mr: support multiple tables")
Signed-off-by: Stefan Wiehler <redacted>
---
net/ipv6/ip6mr.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index b169b27de7e1..39aac81a30f1 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c@@ -2633,27 +2633,31 @@ static int ip6mr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, grp = nla_get_in6_addr(tb[RTA_DST]); tableid = tb[RTA_TABLE] ? nla_get_u32(tb[RTA_TABLE]) : 0; + rcu_read_lock(); mrt = ip6mr_get_table(net, tableid ?: RT_TABLE_DEFAULT); if (!mrt) { + rcu_read_unlock(); NL_SET_ERR_MSG_MOD(extack, "MR table does not exist"); return -ENOENT; } /* entries are added/deleted only under RTNL */ - rcu_read_lock(); cache = ip6mr_cache_find(mrt, &src, &grp); - rcu_read_unlock(); if (!cache) { + rcu_read_unlock(); NL_SET_ERR_MSG_MOD(extack, "MR cache entry not found"); return -ENOENT; } skb = nlmsg_new(mr6_msgsize(false, mrt->maxvif), GFP_KERNEL); - if (!skb) + if (!skb) { + rcu_read_unlock(); return -ENOBUFS; + } err = ip6mr_fill_mroute(mrt, skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, cache, RTM_NEWROUTE, 0); + rcu_read_unlock(); if (err < 0) { kfree_skb(skb); return err;
--
2.42.0