| Message ID | 20241014151247.1902637-9-stefan.wiehler@nokia.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | Lock RCU before calling ip6mr_get_table() | expand |
On Mon, 14 Oct 2024 17:05:54 +0200 Stefan Wiehler wrote: > + rcu_read_lock(); > mrt = ip6mr_get_table(net, raw6_sk(sk)->ip6mr_table ? : RT6_TABLE_DFLT); > + rcu_read_unlock(); > if (!mrt) > return -ENOENT; presumably you're trying to protect mrt with RCU? so using mrt after unlocking is not right, you gotta hold the lock longer
>> + rcu_read_lock(); >> mrt = ip6mr_get_table(net, raw6_sk(sk)->ip6mr_table ? : RT6_TABLE_DFLT); >> + rcu_read_unlock(); >> if (!mrt) >> return -ENOENT; > > presumably you're trying to protect mrt with RCU? > so using mrt after unlocking is not right, you gotta hold the lock > longer Thanks, you're right of course, I'll be fixing this everywhere and send a v6 shortly; also with more extensive reasoning for this series in the cover letter. Kind regards, Stefan
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c index b54353bee2f8..af921e9731ec 100644 --- a/net/ipv6/ip6mr.c +++ b/net/ipv6/ip6mr.c @@ -1845,7 +1845,9 @@ int ip6_mroute_getsockopt(struct sock *sk, int optname, sockptr_t optval, inet_sk(sk)->inet_num != IPPROTO_ICMPV6) return -EOPNOTSUPP; + rcu_read_lock(); mrt = ip6mr_get_table(net, raw6_sk(sk)->ip6mr_table ? : RT6_TABLE_DFLT); + rcu_read_unlock(); if (!mrt) return -ENOENT;
When IPV6_MROUTE_MULTIPLE_TABLES is enabled, calls to ip6mr_get_table() must be done under RCU or RTNL lock. Fixes: d1db275dd3f6 ("ipv6: ip6mr: support multiple tables") Signed-off-by: Stefan Wiehler <stefan.wiehler@nokia.com> --- net/ipv6/ip6mr.c | 2 ++ 1 file changed, 2 insertions(+)