Commit c0e11161 authored Sep 23, 2025 by Michael S. Tsirkin

vhost: vringh: Fix copy_to_iter return value check

The return value of copy_to_iter can't be negative, check whether the
copied length is equal to the requested length instead of checking for
negative values.

Fixes: 309bba39 ("vringh: iterate on iotlb_translate to handle large translations")
Cc: "Stefano Garzarella" <sgarzare@redhat.com>
Cc: zhang jiao <zhangjiao2@cmss.chinamobile.com>
Link: https://lore.kernel.org/all/20250910091739.2999-1-zhangjiao2@cmss.chinamobile.com

Message-ID: <cd637504a6e3967954a9e80fc1b75e8c0978087b.1758723310.git.mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

parent 82a8d0fd

drivers/vhost/vringh.c

+4 −3

Original line number	Diff line number	Diff line
		@@ -1162,6 +1162,7 @@ static inline int copy_to_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)dst,
		len - total_translated, &translated,
		@@ -1179,9 +1180,9 @@ static inline int copy_to_iotlb(const struct vringh vrh, void dst,
		translated);
		}

		ret = copy_to_iter(src, translated, &iter);
		if (ret < 0)
		return ret;
		size = copy_to_iter(src, translated, &iter);
		if (size != translated)
		return -EFAULT;

		src += translated;
		dst += translated;