[PATCH 5.15 215/731] inet: add READ_ONCE(sk->sk_bound_dev_if) in inet_csk_bind_conflict()

Greg Kroah-Hartman
2022-12-28T14:56:20Z

From: Eric Dumazet <edumazet@google.com>

[ Upstream commit d2c135619cb89d1d5693df81ab408c5e8e97e898 ]

inet_csk_bind_conflict() can access sk->sk_bound_dev_if for
unlocked sockets.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/ipv4/inet_connection_sock.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index a53f9bf7886f..8039097546de 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -155,10 +155,14 @@ static int inet_csk_bind_conflict(const struct sock *sk,
*/

sk_for_each_bound(sk2, &tb->owners) {
- if (sk != sk2 &&
- (!sk->sk_bound_dev_if ||
- !sk2->sk_bound_dev_if ||
- sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) {
+ int bound_dev_if2;
+
+ if (sk == sk2)
+ continue;
+ bound_dev_if2 = READ_ONCE(sk2->sk_bound_dev_if);
+ if ((!sk->sk_bound_dev_if ||
+ !bound_dev_if2 ||
+ sk->sk_bound_dev_if == bound_dev_if2)) {
if (reuse && sk2->sk_reuse &&
sk2->sk_state != TCP_LISTEN) {
if ((!relax ||
--
2.35.1