[v3,06/28] softmmu: Replace g_memdup() by g_memdup2()

Commit Message

Philippe Mathieu-Daudé Sept. 3, 2021, 5:44 p.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() wrapper.

Signed-off-by: Philippe Mathieu-Daudé <[e-mail]>
---
 softmmu/memory.c | 2 +-
 softmmu/vl.c     | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

Patch

diff --git a/softmmu/memory.c b/softmmu/memory.c
index bfedaf9c4df..1db019393b6 100644
--- a/softmmu/memory.c
+++ b/softmmu/memory.c
@@ -1140,7 +1140,7 @@  static char *memory_region_escape_name(const char *name)
         bytes += memory_region_need_escape(*p) ? 4 : 1;
     }
     if (bytes == p - name) {
-       return g_memdup(name, bytes + 1);
+        return g_memdup2(name, bytes + 1);
     }
 
     escaped = g_malloc(bytes + 1);
diff --git a/softmmu/vl.c b/softmmu/vl.c
index ea05bb39c50..7a44c63a6ad 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -1154,7 +1154,7 @@  static int parse_fw_cfg(void *opaque, QemuOpts *opts, Error **errp)
     }
     if (nonempty_str(str)) {
         size = strlen(str); /* NUL terminator NOT included in fw_cfg blob */
-        buf = g_memdup(str, size);
+        buf = g_memdup2(str, size);
     } else if (nonempty_str(gen_id)) {
         if (!fw_cfg_add_from_generator(fw_cfg, name, gen_id, errp)) {
             return -1;