[07/28] hw/9pfs: Replace g_memdup() by g_memdup2_qemu()

Commit Message

Philippe Mathieu-Daudé Sept. 3, 2021, 11:06 a.m. UTC

Per https://discourse.gnome.org/t/port-your-module-from-g-memdup-to-g-memdup2-now/5538

  The old API took the size of the memory to duplicate as a guint,
  whereas most memory functions take memory sizes as a gsize. This
  made it easy to accidentally pass a gsize to g_memdup(). For large
  values, that would lead to a silent truncation of the size from 64
  to 32 bits, and result in a heap area being returned which is
  significantly smaller than what the caller expects. This can likely
  be exploited in various modules to cause a heap buffer overflow.

Replace g_memdup() by the safer g_memdup2_qemu() wrapper.

Signed-off-by: Philippe Mathieu-Daudé <[e-mail]>
---
 hw/9pfs/9p-synth.c | 2 +-
 hw/9pfs/9p.c       | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

Patch

diff --git a/hw/9pfs/9p-synth.c b/hw/9pfs/9p-synth.c
index b38088e0664..7d983574af5 100644
--- a/hw/9pfs/9p-synth.c
+++ b/hw/9pfs/9p-synth.c
@@ -497,7 +497,7 @@  static int synth_name_to_path(FsContext *ctx, V9fsPath *dir_path,
 out:
     /* Copy the node pointer to fid */
     g_free(target->data);
-    target->data = g_memdup(&node, sizeof(void *));
+    target->data = g_memdup2_qemu(&node, sizeof(void *));
     target->size = sizeof(void *);
     return 0;
 }
diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
index 2815257f425..5bf1bd7229f 100644
--- a/hw/9pfs/9p.c
+++ b/hw/9pfs/9p.c
@@ -202,7 +202,7 @@  void v9fs_path_copy(V9fsPath *dst, const V9fsPath *src)
 {
     v9fs_path_free(dst);
     dst->size = src->size;
-    dst->data = g_memdup(src->data, src->size);
+    dst->data = g_memdup2_qemu(src->data, src->size);
 }
 
 int v9fs_name_to_path(V9fsState *s, V9fsPath *dirpath,