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authorKuniyuki Iwashima <kuniyu@amazon.com>2024-06-04 09:52:31 -0700
committerPaolo Abeni <pabeni@redhat.com>2024-06-06 12:57:14 +0200
commita9bf9c7dc6a5899c01cb8f6e773a66315a5cd4b7 (patch)
treef03bcb7441f9301a0030360666961331997af287
parenteb0718fb3e97ad0d6f4529b810103451c90adf94 (diff)
af_unix: Annotate data-race of sk->sk_state in unix_stream_connect().
As small optimisation, unix_stream_connect() prefetches the client's sk->sk_state without unix_state_lock() and checks if it's TCP_CLOSE. Later, sk->sk_state is checked again under unix_state_lock(). Let's use READ_ONCE() for the first check and TCP_CLOSE directly for the second check. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
-rw-r--r--net/unix/af_unix.c7
1 files changed, 2 insertions, 5 deletions
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 3bacf47cb94d..84552826530d 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -1481,7 +1481,6 @@ static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
struct sk_buff *skb = NULL;
long timeo;
int err;
- int st;
err = unix_validate_addr(sunaddr, addr_len);
if (err)
@@ -1571,9 +1570,7 @@ restart:
Well, and we have to recheck the state after socket locked.
*/
- st = sk->sk_state;
-
- switch (st) {
+ switch (READ_ONCE(sk->sk_state)) {
case TCP_CLOSE:
/* This is ok... continue with connect */
break;
@@ -1588,7 +1585,7 @@ restart:
unix_state_lock_nested(sk, U_LOCK_SECOND);
- if (sk->sk_state != st) {
+ if (sk->sk_state != TCP_CLOSE) {
unix_state_unlock(sk);
unix_state_unlock(other);
sock_put(other);