[PATCH 6.1 0361/1146] net: Return errno in sk->sk_prot->get_port().

Greg Kroah-Hartman
2022-12-28T15:46:03Z

From: Kuniyuki Iwashima <kuniyu@amazon.com>

[ Upstream commit 7a7160edf1bfde25422262fb26851cef65f695d3 ]

We assume the correct errno is -EADDRINUSE when sk->sk_prot->get_port()
fails, so some ->get_port() functions return just 1 on failure and the
callers return -EADDRINUSE instead.

However, mptcp_get_port() can return -EINVAL. Let's not ignore the error.

Note the only exception is inet_autobind(), all of whose callers return
-EAGAIN instead.

Fixes: cec37a6e41aa ("mptcp: Handle MP_CAPABLE options for outgoing connections")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/ipv4/af_inet.c | 4 ++--
net/ipv4/inet_connection_sock.c | 7 ++++---
net/ipv4/ping.c | 2 +-
net/ipv4/udp.c | 2 +-
net/ipv6/af_inet6.c | 4 ++--
5 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 0da679411330..92d423786251 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -522,9 +522,9 @@ int __inet_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len,
/* Make sure we are allowed to bind here. */
if (snum || !(inet->bind_address_no_port ||
(flags & BIND_FORCE_ADDRESS_NO_PORT))) {
- if (sk->sk_prot->get_port(sk, snum)) {
+ err = sk->sk_prot->get_port(sk, snum);
+ if (err) {
inet->inet_saddr = inet->inet_rcv_saddr = 0;
- err = -EADDRINUSE;
goto out_release_sock;
}
if (!(flags & BIND_FROM_BPF)) {
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 4e84ed21d16f..4a34bc7cb15e 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -471,11 +471,11 @@ int inet_csk_get_port(struct sock *sk, unsigned short snum)
bool reuse = sk->sk_reuse && sk->sk_state != TCP_LISTEN;
bool found_port = false, check_bind_conflict = true;
bool bhash_created = false, bhash2_created = false;
+ int ret = -EADDRINUSE, port = snum, l3mdev;
struct inet_bind_hashbucket *head, *head2;
struct inet_bind2_bucket *tb2 = NULL;
struct inet_bind_bucket *tb = NULL;
bool head2_lock_acquired = false;
- int ret = 1, port = snum, l3mdev;
struct net *net = sock_net(sk);

l3mdev = inet_sk_bound_l3mdev(sk);
@@ -1186,7 +1186,7 @@ int inet_csk_listen_start(struct sock *sk)
{
struct inet_connection_sock *icsk = inet_csk(sk);
struct inet_sock *inet = inet_sk(sk);
- int err = -EADDRINUSE;
+ int err;

reqsk_queue_alloc(&icsk->icsk_accept_queue);

@@ -1202,7 +1202,8 @@ int inet_csk_listen_start(struct sock *sk)
* after validation is complete.
*/
inet_sk_state_store(sk, TCP_LISTEN);
- if (!sk->sk_prot->get_port(sk, inet->inet_num)) {
+ err = sk->sk_prot->get_port(sk, inet->inet_num);
+ if (!err) {
inet->inet_sport = htons(inet->inet_num);

sk_dst_reset(sk);
diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
index 04b4ec07bb06..409ec2a1f95b 100644
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -143,7 +143,7 @@ int ping_get_port(struct sock *sk, unsigned short ident)

fail:
spin_unlock(&ping_table.lock);
- return 1;
+ return -EADDRINUSE;
}
EXPORT_SYMBOL_GPL(ping_get_port);

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 83fdd2b8afd6..2eaf47e23b22 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -235,7 +235,7 @@ int udp_lib_get_port(struct sock *sk, unsigned short snum,
struct udp_table *udptable = sk->sk_prot->h.udp_table;
struct udp_hslot *hslot, *hslot2;
struct net *net = sock_net(sk);
- int error = 1;
+ int error = -EADDRINUSE;

if (!snum) {
DECLARE_BITMAP(bitmap, PORTS_PER_CHAIN);
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index 024191004982..7b0cd54da452 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -409,10 +409,10 @@ static int __inet6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len,
/* Make sure we are allowed to bind here. */
if (snum || !(inet->bind_address_no_port ||
(flags & BIND_FORCE_ADDRESS_NO_PORT))) {
- if (sk->sk_prot->get_port(sk, snum)) {
+ err = sk->sk_prot->get_port(sk, snum);
+ if (err) {
sk->sk_ipv6only = saved_ipv6only;
inet_reset_saddr(sk);
- err = -EADDRINUSE;
goto out;
}
if (!(flags & BIND_FROM_BPF)) {
--
2.35.1