[PATCH 6.6 057/175] tcp: Rearrange tests in inet_csk_bind_conflict().

Greg Kroah-Hartman
2026-03-31T16:26:04Z

From: Kuniyuki Iwashima <kuniyu@amazon.com>

[ Upstream commit 58655bc0ad7ccdd5b53319bcc091cb81b6aee7c3 ]

The following patch adds code in the !inet_use_bhash2_on_bind(sk)
case in inet_csk_bind_conflict().

To avoid adding nest and make the change cleaner, this patch
rearranges tests in inet_csk_bind_conflict().

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: e537dd15d0d4 ("udp: Fix wildcard bind conflict check when using hash2")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/ipv4/inet_connection_sock.c | 40 ++++++++++++++++-----------------
1 file changed, 19 insertions(+), 21 deletions(-)

diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 4a53c538dcaa1..e7751bfab92bb 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -240,9 +240,10 @@ static int inet_csk_bind_conflict(const struct sock *sk,
const struct inet_bind2_bucket *tb2, /* may be null */
bool relax, bool reuseport_ok)
{
- bool reuseport_cb_ok;
- struct sock_reuseport *reuseport_cb;
kuid_t uid = sock_i_uid((struct sock *)sk);
+ struct sock_reuseport *reuseport_cb;
+ bool reuseport_cb_ok;
+ struct sock *sk2;

rcu_read_lock();
reuseport_cb = rcu_dereference(sk->sk_reuseport_cb);
@@ -250,32 +251,29 @@ static int inet_csk_bind_conflict(const struct sock *sk,
reuseport_cb_ok = !reuseport_cb || READ_ONCE(reuseport_cb->num_closed_socks);
rcu_read_unlock();

- /*
- * Unlike other sk lookup places we do not check
+ /* Conflicts with an existing IPV6_ADDR_ANY (if ipv6) or INADDR_ANY (if
+ * ipv4) should have been checked already. We need to do these two
+ * checks separately because their spinlocks have to be acquired/released
+ * independently of each other, to prevent possible deadlocks
+ */
+ if (inet_use_bhash2_on_bind(sk))
+ return tb2 && inet_bhash2_conflict(sk, tb2, uid, relax,
+ reuseport_cb_ok, reuseport_ok);
+
+ /* Unlike other sk lookup places we do not check
* for sk_net here, since _all_ the socks listed
* in tb->owners and tb2->owners list belong
* to the same net - the one this bucket belongs to.
*/
+ sk_for_each_bound(sk2, &tb->owners) {
+ if (!inet_bind_conflict(sk, sk2, uid, relax, reuseport_cb_ok, reuseport_ok))
+ continue;

- if (!inet_use_bhash2_on_bind(sk)) {
- struct sock *sk2;
-
- sk_for_each_bound(sk2, &tb->owners)
- if (inet_bind_conflict(sk, sk2, uid, relax,
- reuseport_cb_ok, reuseport_ok) &&
- inet_rcv_saddr_equal(sk, sk2, true))
- return true;
-
- return false;
+ if (inet_rcv_saddr_equal(sk, sk2, true))
+ return true;
}

- /* Conflicts with an existing IPV6_ADDR_ANY (if ipv6) or INADDR_ANY (if
- * ipv4) should have been checked already. We need to do these two
- * checks separately because their spinlocks have to be acquired/released
- * independently of each other, to prevent possible deadlocks
- */
- return tb2 && inet_bhash2_conflict(sk, tb2, uid, relax, reuseport_cb_ok,
- reuseport_ok);
+ return false;
}

/* Determine if there is a bind conflict with an existing IPV6_ADDR_ANY (if ipv6) or
--
2.51.0