diff --git a/fs/ntfs3/frecord.c b/fs/ntfs3/frecord.c
index 3ad309d38fe8..a9d1fc0b812a 100644
--- a/fs/ntfs3/frecord.c
+++ b/fs/ntfs3/frecord.c
@@ -2455,6 +2455,15 @@ int ni_read_frame(struct ntfs_inode *ni, u64 frame_vbo, struct page **pages,
 			err = unc_size;
 		else if (!unc_size || unc_size > frame_size)
 			err = -EINVAL;
+		else if (unc_size < frame_size) {
+			/*
+			 * Partial decompress: zero the [unc_size, frame_size)
+			 * tail.  decompress_lznt() leaves it untouched, so
+			 * without this the freshly vmapped pages would expose
+			 * uninitialized kernel memory to userspace.
+			 */
+			memset(frame_mem + unc_size, 0, frame_size - unc_size);
+		}
 	}
 	if (!err && valid_size < frame_vbo + frame_size) {
 		size_t ok = valid_size - frame_vbo;