Patch "xsk: Skip polling event check for unbound socket" has been added to the 6.1-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    xsk: Skip polling event check for unbound socket

to the 6.1-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:
     xsk-skip-polling-event-check-for-unbound-socket.patch
and it can be found in the queue-6.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 6b36b9ac45d3d7864f6a1c3ff3ba87647019cb3d
Author: Yewon Choi <woni9911@xxxxxxxxx>
Date:   Fri Dec 1 15:10:52 2023 +0900

    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@xxxxxxxxx>
    Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
    Acked-by: Magnus Karlsson <magnus.karlsson@xxxxxxxxx>
    Link: https://lore.kernel.org/bpf/20231201061048.GA1510@libra05
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

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;
 }