[PATCH 3/3] inet: fix improper empty comparison

From: josef
Date: Mon Sep 18 2017 - 12:29:39 EST

From: Josef Bacik <jbacik@xxxxxx>

When doing my reuseport rework I screwed up and changed a

if (hlist_empty(&tb->owners))


if (!hlist_empty(&tb->owners))

This is obviously bad as all of the reuseport/reuse logic was reversed,
which caused weird problems like allowing an ipv4 bind conflict if we
opened an ipv4 only socket on a port followed by an ipv6 only socket on
the same port.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: b9470c27607b ("inet: kill smallest_size and smallest_port")
Reported-by: Cole Robinson <crobinso@xxxxxxxxxx>
Signed-off-by: Josef Bacik <jbacik@xxxxxx>
net/ipv4/inet_connection_sock.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index a1bf30438bc5..c039c937ba90 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -321,7 +321,7 @@ int inet_csk_get_port(struct sock *sk, unsigned short snum)
goto fail_unlock;
- if (!hlist_empty(&tb->owners)) {
+ if (hlist_empty(&tb->owners)) {
tb->fastreuse = reuse;
if (sk->sk_reuseport) {
tb->fastreuseport = FASTREUSEPORT_ANY;