This is a note to let you know that I've just added the patch titled
af_unix: Annotate data-races around sk->sk_state in UNIX_DIAG.
to the 4.19-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_state-in-un.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 8b80a7233bda7652714e303e70f74216bd3b3c24
Author: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Date: Tue Jun 4 09:52:35 2024 -0700
af_unix: Annotate data-races around sk->sk_state in UNIX_DIAG.
[ Upstream commit 0aa3be7b3e1f8f997312cc4705f8165e02806f8f ]
While dumping AF_UNIX sockets via UNIX_DIAG, sk->sk_state is read
locklessly.
Let's use READ_ONCE() there.
Note that the result could be inconsistent if the socket is dumped
during the state change. This is common for other SOCK_DIAG and
similar interfaces.
Fixes: c9da99e6475f ("unix_diag: Fixup RQLEN extension report")
Fixes: 2aac7a2cb0d9 ("unix_diag: Pending connections IDs NLA")
Fixes: 45a96b9be6ec ("unix_diag: Dumping all sockets core")
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/diag.c b/net/unix/diag.c
index d6ceac688defc..f27b4e55da0e8 100644
--- a/net/unix/diag.c
+++ b/net/unix/diag.c
@@ -61,7 +61,7 @@ static int sk_diag_dump_icons(struct sock *sk, struct sk_buff *nlskb)
u32 *buf;
int i;
- if (sk->sk_state == TCP_LISTEN) {
+ if (READ_ONCE(sk->sk_state) == TCP_LISTEN) {
spin_lock(&sk->sk_receive_queue.lock);
attr = nla_reserve(nlskb, UNIX_DIAG_ICONS,
@@ -99,7 +99,7 @@ static int sk_diag_show_rqlen(struct sock *sk, struct sk_buff *nlskb)
{
struct unix_diag_rqlen rql;
- if (sk->sk_state == TCP_LISTEN) {
+ if (READ_ONCE(sk->sk_state) == TCP_LISTEN) {
rql.udiag_rqueue = sk->sk_receive_queue.qlen;
rql.udiag_wqueue = sk->sk_max_ack_backlog;
} else {
@@ -124,7 +124,7 @@ static int sk_diag_fill(struct sock *sk, struct sk_buff *skb, struct unix_diag_r
rep = nlmsg_data(nlh);
rep->udiag_family = AF_UNIX;
rep->udiag_type = sk->sk_type;
- rep->udiag_state = sk->sk_state;
+ rep->udiag_state = READ_ONCE(sk->sk_state);
rep->pad = 0;
rep->udiag_ino = sk_ino;
sock_diag_save_cookie(sk, rep->udiag_cookie);
@@ -202,7 +202,7 @@ static int unix_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
continue;
if (num < s_num)
goto next;
- if (!(req->udiag_states & (1 << sk->sk_state)))
+ if (!(req->udiag_states & (1 << READ_ONCE(sk->sk_state))))
goto next;
if (sk_diag_dump(sk, skb, req,
NETLINK_CB(cb->skb).portid,
