UPSTREAM: 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: f87d0fbb57 ("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>
(cherry picked from commit dbd29e0752)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I989cc3d74401507f6b9c282971e60ecb21785895
This commit is contained in:
Xie Yongji
2022-05-05 18:09:10 +08:00
committed by Treehugger Robot
parent 6e2a35571a
commit fa4bbdf264

View File

@@ -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;
}