vringh: Fix loop descriptors check in the indirect cases

[ 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: 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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Xie Yongji
2022-05-05 18:09:10 +08:00
committed by Greg Kroah-Hartman
parent 3966522c6b
commit 29c3f932b4

View File

@@ -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;
}