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authorXie Yongji <xieyongji@bytedance.com>2022-05-05 18:09:10 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-06-14 18:12:02 +0200
commit1a36f77dc23c3768e06cdc32777b2d85be7f4150 (patch)
treeb9f9f81c7a99bcf1c87bfe1874ae32885372c336
parenta3f9b0afd8b4fcec563e97cedae84636e1a468d8 (diff)
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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: 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>
-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 4653de001e26..264cbe385a63 100644
--- a/drivers/vhost/vringh.c
+++ b/drivers/vhost/vringh.c
@@ -264,7 +264,7 @@ __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;
@@ -321,7 +321,12 @@ __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;
@@ -383,6 +388,7 @@ __vringh_iov(struct vringh *vrh, u16 i,
i = return_from_indirect(vrh, &up_next,
&descs, &desc_max);
slow = false;
+ indirect_count = 0;
} else
break;
}