+++ /dev/null
-From 630abd0c70f272b36361348e9ee7d6a71577b72f Mon Sep 17 00:00:00 2001
-From: Li Qiang <liqiang6-s@360.cn>
-Date: Tue, 11 Oct 2016 09:27:45 +0200
-Subject: [PATCH 4/4] 9pfs: allocate space for guest originated empty strings
-
-If a guest sends an empty string paramater to any 9P operation, the current
-code unmarshals it into a V9fsString equal to { .size = 0, .data = NULL }.
-
-This is unfortunate because it can cause NULL pointer dereference to happen
-at various locations in the 9pfs code. And we don't want to check str->data
-everywhere we pass it to strcmp() or any other function which expects a
-dereferenceable pointer.
-
-This patch enforces the allocation of genuine C empty strings instead, so
-callers don't have to bother.
-
-Out of all v9fs_iov_vunmarshal() users, only v9fs_xattrwalk() checks if
-the returned string is empty. It now uses v9fs_string_size() since
-name.data cannot be NULL anymore.
-
-Signed-off-by: Li Qiang <liqiang6-s@360.cn>
-[groug, rewritten title and changelog,
- fix empty string check in v9fs_xattrwalk()]
-Signed-off-by: Greg Kurz <groug@kaod.org>
----
- fsdev/9p-iov-marshal.c | 2 +-
- hw/9pfs/9p.c | 2 +-
- 2 files changed, 2 insertions(+), 2 deletions(-)
-
-diff --git a/fsdev/9p-iov-marshal.c b/fsdev/9p-iov-marshal.c
-index 663cad5..1d16f8d 100644
---- a/fsdev/9p-iov-marshal.c
-+++ b/fsdev/9p-iov-marshal.c
-@@ -125,7 +125,7 @@ ssize_t v9fs_iov_vunmarshal(struct iovec *out_sg, int out_num, size_t offset,
- str->data = g_malloc(str->size + 1);
- copied = v9fs_unpack(str->data, out_sg, out_num, offset,
- str->size);
-- if (copied > 0) {
-+ if (copied >= 0) {
- str->data[str->size] = 0;
- } else {
- v9fs_string_free(str);
-diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
-index 54e18a2..75ba5f1 100644
---- a/hw/9pfs/9p.c
-+++ b/hw/9pfs/9p.c
-@@ -3161,7 +3161,7 @@ static void v9fs_xattrwalk(void *opaque)
- goto out;
- }
- v9fs_path_copy(&xattr_fidp->path, &file_fidp->path);
-- if (name.data == NULL) {
-+ if (!v9fs_string_size(&name)) {
- /*
- * listxattr request. Get the size first
- */
---
-2.1.4
-