From: Michael S. Tsirkin Date: Thu, 25 Sep 2025 06:04:08 +0000 (-0400) Subject: vhost: vringh: Fix copy_to_iter return value check X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=439263376c2c4e126cac0d07e4987568de4eaba5;p=users%2Fhch%2Fmisc.git 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. Cc: zhang jiao Link: https://lore.kernel.org/all/20250910091739.2999-1-zhangjiao2@cmss.chinamobile.com Signed-off-by: Michael S. Tsirkin Reviewed-by: Simon Horman Fixes: 309bba39c945 ("vringh: iterate on iotlb_translate to handle large translations") Link: https://patch.msgid.link/cd637504a6e3967954a9e80fc1b75e8c0978087b.1758723310.git.mst@redhat.com Signed-off-by: Jakub Kicinski --- diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c index 9f27c3f6091b..1778eff7ab00 100644 --- a/drivers/vhost/vringh.c +++ b/drivers/vhost/vringh.c @@ -1161,6 +1161,7 @@ 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, @@ -1178,9 +1179,9 @@ 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;