This is a note to let you know that I've just added the patch titled
af_unix: Annotate data-races around sk->sk_sndbuf.
to the 6.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
af_unix-annotate-data-races-around-sk-sk_sndbuf.patch
and it can be found in the queue-6.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit b0197ba851a3df3627b336181494acff9065bb19
Author: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Date: Tue Jun 4 09:52:36 2024 -0700
af_unix: Annotate data-races around sk->sk_sndbuf.
[ Upstream commit b0632e53e0da8054e36bc973f0eec69d30f1b7c6 ]
sk_setsockopt() changes sk->sk_sndbuf under lock_sock(), but it's
not used in af_unix.c.
Let's use READ_ONCE() to read sk->sk_sndbuf in unix_writable(),
unix_dgram_sendmsg(), and unix_stream_sendmsg().
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 9f266a7679cbc..84bc1de2fd967 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -533,7 +533,7 @@ static int unix_dgram_peer_wake_me(struct sock *sk, struct sock *other)
static int unix_writable(const struct sock *sk, unsigned char state)
{
return state != TCP_LISTEN &&
- (refcount_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf;
+ (refcount_read(&sk->sk_wmem_alloc) << 2) <= READ_ONCE(sk->sk_sndbuf);
}
static void unix_write_space(struct sock *sk)
@@ -2014,7 +2014,7 @@ static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
}
err = -EMSGSIZE;
- if (len > sk->sk_sndbuf - 32)
+ if (len > READ_ONCE(sk->sk_sndbuf) - 32)
goto out;
if (len > SKB_MAX_ALLOC) {
@@ -2294,7 +2294,7 @@ static int unix_stream_sendmsg(struct socket *sock, struct msghdr *msg,
&err, 0);
} else {
/* Keep two messages in the pipe so it schedules better */
- size = min_t(int, size, (sk->sk_sndbuf >> 1) - 64);
+ size = min_t(int, size, (READ_ONCE(sk->sk_sndbuf) >> 1) - 64);
/* allow fallback to order-0 allocations */
size = min_t(int, size, SKB_MAX_HEAD(0) + UNIX_SKB_FRAGS_SZ);
