5.4-stable review patch. If anyone has any objections, please let me know.
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From: Kuniyuki Iwashima kuniyu@amazon.com
[ 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@amazon.com Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/unix/diag.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/net/unix/diag.c b/net/unix/diag.c index 2975e7a061d0b..4666fabb04933 100644 --- a/net/unix/diag.c +++ b/net/unix/diag.c @@ -64,7 +64,7 @@ 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, @@ -102,7 +102,7 @@ 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 { @@ -135,7 +135,7 @@ 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); @@ -218,7 +218,7 @@ 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, sk_user_ns(skb->sk), NETLINK_CB(cb->skb).portid,