netlink: Fix rmem check in netlink_broadcast_deliver().

commit a3c4a125ec725cefb40047eb05ff9eafd57830b4 upstream.

We need to allow queuing at least one skb even when skb is
larger than sk->sk_rcvbuf.

The cited commit made a mistake while converting a condition
in netlink_broadcast_deliver().

Let's correct the rmem check for the allow-one-skb rule.

Fixes: ae8f160e7eb24 ("netlink: Fix wraparounds of sk->sk_rmem_alloc.")
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250711053208.2965945-1-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 6f71b4c84d1d29212da5bebaf5cea345b84116a7..9d338562f346ce1ecc7be451838db54e6f87a6fe 100644 (file)
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -1391,7 +1391,7 @@ static int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb)
        rmem = atomic_add_return(skb->truesize, &sk->sk_rmem_alloc);
        rcvbuf = READ_ONCE(sk->sk_rcvbuf);
 
-       if ((rmem != skb->truesize || rmem <= rcvbuf) &&
+       if ((rmem == skb->truesize || rmem <= rcvbuf) &&
            !test_bit(NETLINK_S_CONGESTED, &nlk->state)) {
                netlink_skb_set_owner_r(skb, sk);
                __netlink_sendskb(sk, skb);