From 98047313cdb46828093894d0ac8b1183b8b317f9 Mon Sep 17 00:00:00 2001
From: Stefano Garzarella <sgarzare@redhat.com>
Date: Wed, 9 Nov 2022 11:25:03 +0100
Subject: [PATCH] vhost: fix range used in translate_desc()
Git-commit: 98047313cdb46828093894d0ac8b1183b8b317f9
Patch-mainline: v6.2-rc3
References: git-fixes

vhost_iotlb_itree_first() requires `start` and `last` parameters
to search for a mapping that overlaps the range.

In translate_desc() we cyclically call vhost_iotlb_itree_first(),
incrementing `addr` by the amount already translated, so rightly
we move the `start` parameter passed to vhost_iotlb_itree_first(),
but we should hold the `last` parameter constant.

Let's fix it by saving the `last` parameter value before incrementing
`addr` in the loop.

Fixes: a9709d6874d5 ("vhost: convert pre sorted vhost memory array to interval tree")
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Message-id: <20221109102503.18816-3-sgarzare@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/vhost/vhost.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 5c9fe3c9c364..cbe72bfd2f1f 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -2053,7 +2053,7 @@ static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len,
 	struct vhost_dev *dev = vq->dev;
 	struct vhost_iotlb *umem = dev->iotlb ? dev->iotlb : dev->umem;
 	struct iovec *_iov;
-	u64 s = 0;
+	u64 s = 0, last = addr + len - 1;
 	int ret = 0;
 
 	while ((u64)len > s) {
@@ -2063,7 +2063,7 @@ static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len,
 			break;
 		}
 
-		map = vhost_iotlb_itree_first(umem, addr, addr + len - 1);
+		map = vhost_iotlb_itree_first(umem, addr, last);
 		if (map == NULL || map->start > addr) {
 			if (umem != dev->iotlb) {
 				ret = -EFAULT;
-- 
2.35.3