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

On Sun, Sep 21, 2025 at 04:59:36PM -0400, Michael S. Tsirkin wrote:

On Wed, Sep 10, 2025 at 05:17:38PM +0800, zhangjiao2 wrote:

quoted

From: zhang jiao <redacted>

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 <redacted>

Well I don't see a fix for copy_to_iter here.


                ret = copy_to_iter(src, translated, &iter);
                if (ret < 0)
                        return ret;

to clarify, pls send an additional patch to copy that one.

quoted

---
 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