From: Yewon Choi <woni9911@gmail.com>
Date: Fri, 1 Dec 2023 06:10:52 +0000 (+0900)
Subject: xsk: Skip polling event check for unbound socket
X-Git-Tag: v6.1.68~160
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2c0cbb97b118243562253bb653fe3f5910d2d0df;p=thirdparty%2Fkernel%2Fstable.git

xsk: Skip polling event check for unbound socket

[ Upstream commit e4d008d49a7135214e0ee70537405b6a069e3a3f ]

In xsk_poll(), checking available events and setting mask bits should
be executed only when a socket has been bound. Setting mask bits for
unbound socket is meaningless.

Currently, it checks events even when xsk_check_common() failed.
To prevent this, we move goto location (skip_tx) after that checking.

Fixes: 1596dae2f17e ("xsk: check IFF_UP earlier in Tx path")
Signed-off-by: Yewon Choi <woni9911@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/bpf/20231201061048.GA1510@libra05
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index f7592638e61d3..5c8e02d56fd43 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -722,7 +722,7 @@ static __poll_t xsk_poll(struct file *file, struct socket *sock,
 
 	rcu_read_lock();
 	if (xsk_check_common(xs))
-		goto skip_tx;
+		goto out;
 
 	pool = xs->pool;
 
@@ -734,12 +734,11 @@ static __poll_t xsk_poll(struct file *file, struct socket *sock,
 			xsk_generic_xmit(sk);
 	}
 
-skip_tx:
 	if (xs->rx && !xskq_prod_is_empty(xs->rx))
 		mask |= EPOLLIN | EPOLLRDNORM;
 	if (xs->tx && xsk_tx_writeable(xs))
 		mask |= EPOLLOUT | EPOLLWRNORM;
-
+out:
 	rcu_read_unlock();
 	return mask;
 }