--- /dev/null
+From 6b54a0d0b606da5c44744339024bd63591b176a7 Mon Sep 17 00:00:00 2001
+From: Sasha Levin <sashal@kernel.org>
+Date: Thu, 5 May 2022 18:09:10 +0800
+Subject: vringh: Fix loop descriptors check in the indirect cases
+
+From: Xie Yongji <xieyongji@bytedance.com>
+
+[ Upstream commit dbd29e0752286af74243cf891accf472b2f3edd8 ]
+
+We should use size of descriptor chain to test loop condition
+in the indirect case. And another statistical count is also introduced
+for indirect descriptors to avoid conflict with the statistical count
+of direct descriptors.
+
+Fixes: f87d0fbb5798 ("vringh: host-side implementation of virtio rings.")
+Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
+Signed-off-by: Fam Zheng <fam.zheng@bytedance.com>
+Message-Id: <20220505100910.137-1-xieyongji@bytedance.com>
+Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
+Acked-by: Jason Wang <jasowang@redhat.com>
+Signed-off-by: Sasha Levin <sashal@kernel.org>
+---
+ drivers/vhost/vringh.c | 10 ++++++++--
+ 1 file changed, 8 insertions(+), 2 deletions(-)
+
+diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c
+index c23045aa9873..a764d36c4d38 100644
+--- a/drivers/vhost/vringh.c
++++ b/drivers/vhost/vringh.c
+@@ -263,7 +263,7 @@ __vringh_iov(struct vringh *vrh, u16 i,
+ gfp_t gfp,
+ int (*copy)(void *dst, const void *src, size_t len))
+ {
+- int err, count = 0, up_next, desc_max;
++ int err, count = 0, indirect_count = 0, up_next, desc_max;
+ struct vring_desc desc, *descs;
+ struct vringh_range range = { -1ULL, 0 }, slowrange;
+ bool slow = false;
+@@ -320,7 +320,12 @@ __vringh_iov(struct vringh *vrh, u16 i,
+ continue;
+ }
+
+- if (count++ == vrh->vring.num) {
++ if (up_next == -1)
++ count++;
++ else
++ indirect_count++;
++
++ if (count > vrh->vring.num || indirect_count > desc_max) {
+ vringh_bad("Descriptor loop in %p", descs);
+ err = -ELOOP;
+ goto fail;
+@@ -382,6 +387,7 @@ __vringh_iov(struct vringh *vrh, u16 i,
+ i = return_from_indirect(vrh, &up_next,
+ &descs, &desc_max);
+ slow = false;
++ indirect_count = 0;
+ } else
+ break;
+ }
+--
+2.35.1
+