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authorXie Yongji <xieyongji@bytedance.com>2022-05-05 18:09:10 +0800
committerMichael S. Tsirkin <mst@redhat.com>2022-06-08 08:56:03 -0400
commitdbd29e0752286af74243cf891accf472b2f3edd8 (patch)
treeb1469cec62f38eee776e02b7cf6fa9d1b0a87168 /drivers/vhost
parentf38b3c6a788f75da151b46c7da61ff26649e1843 (diff)
downloadlinux-dbd29e0752286af74243cf891accf472b2f3edd8.tar.bz2
vringh: Fix loop descriptors check in the indirect cases
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>
Diffstat (limited to 'drivers/vhost')
-rw-r--r--drivers/vhost/vringh.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c
index 14e2043d7685..eab55accf381 100644
--- a/drivers/vhost/vringh.c
+++ b/drivers/vhost/vringh.c
@@ -292,7 +292,7 @@ __vringh_iov(struct vringh *vrh, u16 i,
int (*copy)(const struct vringh *vrh,
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;
@@ -349,7 +349,12 @@ __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;
@@ -411,6 +416,7 @@ __vringh_iov(struct vringh *vrh, u16 i,
i = return_from_indirect(vrh, &up_next,
&descs, &desc_max);
slow = false;
+ indirect_count = 0;
} else
break;
}