This is a note to let you know that I've just added the patch titled
vhost/vsock: fix incorrect used length reported to the guest
to the 4.9-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:
vhost-vsock-fix-incorrect-used-length-reported-to-the-guest.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 49d8c5ffad07ca014cfae72a1b9b8c52b6ad9cb8 Mon Sep 17 00:00:00 2001
From: Stefano Garzarella <sgarzare@xxxxxxxxxx>
Date: Mon, 22 Nov 2021 17:35:24 +0100
Subject: vhost/vsock: fix incorrect used length reported to the guest
From: Stefano Garzarella <sgarzare@xxxxxxxxxx>
commit 49d8c5ffad07ca014cfae72a1b9b8c52b6ad9cb8 upstream.
The "used length" reported by calling vhost_add_used() must be the
number of bytes written by the device (using "in" buffers).
In vhost_vsock_handle_tx_kick() the device only reads the guest
buffers (they are all "out" buffers), without writing anything,
so we must pass 0 as "used length" to comply virtio spec.
Fixes: 433fc58e6bf2 ("VSOCK: Introduce vhost_vsock.ko")
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Halil Pasic <pasic@xxxxxxxxxxxxx>
Suggested-by: Jason Wang <jasowang@xxxxxxxxxx>
Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20211122163525.294024-2-sgarzare@xxxxxxxxxx
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Reviewed-by: Stefan Hajnoczi <stefanha@xxxxxxxxxx>
Reviewed-by: Halil Pasic <pasic@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/vhost/vsock.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -406,7 +406,7 @@ static void vhost_vsock_handle_tx_kick(s
else
virtio_transport_free_pkt(pkt);
- vhost_add_used(vq, head, sizeof(pkt->hdr) + len);
+ vhost_add_used(vq, head, 0);
added = true;
}
Patches currently in stable-queue which might be from sgarzare@xxxxxxxxxx are
queue-4.9/vhost-vsock-fix-incorrect-used-length-reported-to-the-guest.patch
