6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Dumazet <edumazet@xxxxxxxxxx>
[ Upstream commit fde6f897f2a184546bf5516ac736523ef24dc6a7 ]
These functions have races when they:
1) Write sk->sk_err
2) call sk_error_report(sk)
3) call tcp_done(sk)
As described in prior patches in this series:
An smp_wmb() is missing.
We should call tcp_done() before sk_error_report(sk)
to have consistent tcp_poll() results on SMP hosts.
Use tcp_done_with_error() where we centralized the
correct sequence.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Acked-by: Neal Cardwell <ncardwell@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240528125253.1966136-5-edumazet@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/ipv4/tcp_ipv4.c | 11 +++--------
net/ipv6/tcp_ipv6.c | 10 +++-------
2 files changed, 6 insertions(+), 15 deletions(-)
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 7c2ca4df0daa3..48ec2c1777d45 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -602,15 +602,10 @@ int tcp_v4_err(struct sk_buff *skb, u32 info)
ip_icmp_error(sk, skb, err, th->dest, info, (u8 *)th);
- if (!sock_owned_by_user(sk)) {
- WRITE_ONCE(sk->sk_err, err);
-
- sk_error_report(sk);
-
- tcp_done(sk);
- } else {
+ if (!sock_owned_by_user(sk))
+ tcp_done_with_error(sk, err);
+ else
WRITE_ONCE(sk->sk_err_soft, err);
- }
goto out;
}
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 07bcb690932e1..d0034916d386b 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -488,14 +488,10 @@ static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
ipv6_icmp_error(sk, skb, err, th->dest, ntohl(info), (u8 *)th);
- if (!sock_owned_by_user(sk)) {
- WRITE_ONCE(sk->sk_err, err);
- sk_error_report(sk); /* Wake people up to see the error (see connect in sock.c) */
-
- tcp_done(sk);
- } else {
+ if (!sock_owned_by_user(sk))
+ tcp_done_with_error(sk, err);
+ else
WRITE_ONCE(sk->sk_err_soft, err);
- }
goto out;
case TCP_LISTEN:
break;
--
2.43.0
