[PATCH] vhost: vringh: Modify the return value check

zhangjiao2
2025-09-10T09:17:53Z

From: zhang jiao <zhangjiao2@cmss.chinamobile.com>

The return value of copy_from_iter and copy_to_iter can't be negative,
check whether the copied lengths are equal.

Signed-off-by: zhang jiao <zhangjiao2@cmss.chinamobile.com>
---
drivers/vhost/vringh.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c
index 9f27c3f6091b..0c8a17cbb22e 100644
--- a/drivers/vhost/vringh.c
+++ b/drivers/vhost/vringh.c
@@ -1115,6 +1115,7 @@ static inline int copy_from_iotlb(const struct vringh *vrh, void *dst,
struct iov_iter iter;
u64 translated;
int ret;
+ size_t size;

ret = iotlb_translate(vrh, (u64)(uintptr_t)src,
len - total_translated, &translated,
@@ -1132,9 +1133,9 @@ static inline int copy_from_iotlb(const struct vringh *vrh, void *dst,
translated);
}

- ret = copy_from_iter(dst, translated, &iter);
- if (ret < 0)
- return ret;
+ size = copy_from_iter(dst, translated, &iter);
+ if (size != translated)
+ return -EFAULT;

src += translated;
dst += translated;
--
2.33.0