diff options
| author | Eric Dumazet <edumazet@google.com> | 2025-09-16 16:09:44 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-12-03 12:45:13 +0100 |
| commit | 58894600b548f440a6c76253d356691c3eeffe02 (patch) | |
| tree | 8e941e4508ccab022fd4f034975a5fd46742b15a | |
| parent | ac91ada020c161f8a60d16d54568750d5ec0204a (diff) | |
ipv6: np->rxpmtu race annotation
[ Upstream commit 9fba1eb39e2f74d2002c5cbcf1d4435d37a4f752 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -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 731485b18de3..90d828c98b73 100644 --- a/net/ipv6/raw.c +++ b/net/ipv6/raw.c @@ -474,7 +474,7 @@ 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, noblock, &err); diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index db948e3a9bdc..3ed835b30804 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -297,7 +297,7 @@ 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: |