diff options
| author | Eric Dumazet <edumazet@google.com> | 2025-09-16 16:09:44 +0000 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2025-09-18 10:17:09 +0200 |
| commit | 9fba1eb39e2f74d2002c5cbcf1d4435d37a4f752 (patch) | |
| tree | 4cc67eb26e93c7de2a4037d044381eb74228d2cc | |
| parent | 5489f333ef993bfceebce9ae98944f04eaafcc30 (diff) | |
ipv6: np->rxpmtu race annotation
Add READ_ONCE() annotations because np->rxpmtu can be changed
while udpv6_recvmsg() and rawv6_recvmsg() read it.
Since this is a very rarely used feature, and that udpv6_recvmsg()
and rawv6_recvmsg() read np->rxopt anyway, change the test order
so that np->rxpmtu does not need to be in a hot cache line.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250916160951.541279-4-edumazet@google.com
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
| -rw-r--r-- | net/ipv6/raw.c | 2 | ||||
| -rw-r--r-- | net/ipv6/udp.c | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c index 4ae07a67b4d4..e369f54844dd 100644 --- a/net/ipv6/raw.c +++ b/net/ipv6/raw.c @@ -445,7 +445,7 @@ static int rawv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, if (flags & MSG_ERRQUEUE) return ipv6_recv_error(sk, msg, len, addr_len); - if (np->rxpmtu && np->rxopt.bits.rxpmtu) + if (np->rxopt.bits.rxpmtu && READ_ONCE(np->rxpmtu)) return ipv6_recv_rxpmtu(sk, msg, len, addr_len); skb = skb_recv_datagram(sk, flags, &err); diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index b70369f3cd32..e87d0ef861f8 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -479,7 +479,7 @@ int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, if (flags & MSG_ERRQUEUE) return ipv6_recv_error(sk, msg, len, addr_len); - if (np->rxpmtu && np->rxopt.bits.rxpmtu) + if (np->rxopt.bits.rxpmtu && READ_ONCE(np->rxpmtu)) return ipv6_recv_rxpmtu(sk, msg, len, addr_len); try_again: |