6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Dumazet edumazet@google.com
[ Upstream commit 4746b36b1abe11ca32987b2d21e1e770deab17cc ]
For some reason sctp_poll() generates EPOLLERR if sk->sk_error_queue is not empty but recvmsg() can not drain the error queue yet.
This is needed to better support timestamping.
I had to export inet_recv_error(), since sctp can be compiled as a module.
Signed-off-by: Eric Dumazet edumazet@google.com Cc: Marcelo Ricardo Leitner marcelo.leitner@gmail.com Cc: Willem de Bruijn willemb@google.com Acked-by: Xin Long lucien.xin@gmail.com Link: https://lore.kernel.org/r/20231212145550.3872051-1-edumazet@google.com Signed-off-by: Jakub Kicinski kuba@kernel.org Stable-dep-of: a562c0a2d651 ("sctp: fix busy polling") Signed-off-by: Sasha Levin sashal@kernel.org --- net/ipv4/af_inet.c | 1 + net/sctp/socket.c | 3 +++ 2 files changed, 4 insertions(+)
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index 347c3768df6e..c13b8ed63f87 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -1642,6 +1642,7 @@ int inet_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len) #endif return -EINVAL; } +EXPORT_SYMBOL(inet_recv_error);
int inet_gro_complete(struct sk_buff *skb, int nhoff) { diff --git a/net/sctp/socket.c b/net/sctp/socket.c index e25dc1709131..da56832179f0 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -2098,6 +2098,9 @@ static int sctp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, pr_debug("%s: sk:%p, msghdr:%p, len:%zd, flags:0x%x, addr_len:%p)\n", __func__, sk, msg, len, flags, addr_len);
+ if (unlikely(flags & MSG_ERRQUEUE)) + return inet_recv_error(sk, msg, len, addr_len); + lock_sock(sk);
if (sctp_style(sk, TCP) && !sctp_sstate(sk, ESTABLISHED) &&