diff --git a/block/bio.c b/block/bio.c
index a1c74f10d604a535b0740e3c4051b33b71a0435a..9d70ebe4122cf3898674851be72f1ea5f2070f12 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -578,7 +578,8 @@ void bio_truncate(struct bio *bio, unsigned new_size)
 				offset = new_size - done;
 			else
 				offset = 0;
-			zero_user(bv.bv_page, offset, bv.bv_len - offset);
+			zero_user(bv.bv_page, bv.bv_offset + offset,
+				  bv.bv_len - offset);
 			truncated = true;
 		}
 		done += bv.bv_len;