From f85efa9b0f5381874f727bd98f56787840313f0b Mon Sep 17 00:00:00 2001
From: Stefano Garzarella <sgarzare@redhat.com>
Date: Wed, 9 Nov 2022 11:25:02 +0100
Subject: [PATCH] vringh: fix range used in iotlb_translate()
Git-commit: f85efa9b0f5381874f727bd98f56787840313f0b
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 iotlb_translate() 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: 9ad9c49cfe97 ("vringh: IOTLB support")
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Message-id: <20221109102503.18816-2-sgarzare@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/vhost/vringh.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c
index c9f5c8ea3afb..33eb941fcf15 100644
--- a/drivers/vhost/vringh.c
+++ b/drivers/vhost/vringh.c
@@ -1102,7 +1102,7 @@ static int iotlb_translate(const struct vringh *vrh,
 	struct vhost_iotlb_map *map;
 	struct vhost_iotlb *iotlb = vrh->iotlb;
 	int ret = 0;
-	u64 s = 0;
+	u64 s = 0, last = addr + len - 1;
 
 	spin_lock(vrh->iotlb_lock);
 
@@ -1114,8 +1114,7 @@ static int iotlb_translate(const struct vringh *vrh,
 			break;
 		}
 
-		map = vhost_iotlb_itree_first(iotlb, addr,
-					      addr + len - 1);
+		map = vhost_iotlb_itree_first(iotlb, addr, last);
 		if (!map || map->start > addr) {
 			ret = -EINVAL;
 			break;
-- 
2.35.3