[PATCH v3 00/28] glib: Replace g_memdup() by g_memdup2()

[Philippe Mathieu-Daudé]

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.

g_memdup() as been deprecated in GLib 2.68. Since QEMU defines
GLIB_VERSION_MAX_ALLOWED to GLIB_VERSION_2_56, the deprecation
is not displayed (on GLib >= 2.68 such available on Fedora 34).
However the function is still unsafe, so it is better to avoid
its use.

This series provides the safely equivalent g_memdup2() wrapper,
and replace all g_memdup() calls by it.

The previous link recommend to audit the call sites. Most of the
calls use byte_size=sizeof(STRUCT), and no STRUCT appears to be
> 4GiB.  Few calls use unsigned/size_t/uint16_t. Where code is
doing multiplication, patches are sent as RFC. In particular:
    hw/net/virtio-net.c
    hw/virtio/virtio-crypto.c

Since v1:
- Added missing g_memdup2 -> g_memdup2_qemu compat definition (danpb)
- Do not call g_memdup2_qemu() but directly g_memdup2() (danpb)

Tested with the following snippet:
-- >8 --
diff --git a/include/glib-compat.h b/include/glib-compat.h
index 8d01a8c01fb..2b33dea71a8 100644
--- a/include/glib-compat.h
+++ b/include/glib-compat.h
@@ -21,3 +21,3 @@
  */
-#define GLIB_VERSION_MIN_REQUIRED GLIB_VERSION_2_56
+#define GLIB_VERSION_MIN_REQUIRED GLIB_VERSION_2_68

@@ -26,3 +26,3 @@
  */
-#define GLIB_VERSION_MAX_ALLOWED GLIB_VERSION_2_56
+#define GLIB_VERSION_MAX_ALLOWED GLIB_VERSION_2_68

---

Philippe Mathieu-Daudé (28):
  hw/hyperv/vmbus: Remove unused vmbus_load/save_req()
  glib-compat: Introduce g_memdup2() wrapper
  qapi: Replace g_memdup() by g_memdup2()
  accel/tcg: Replace g_memdup() by g_memdup2()
  block/qcow2-bitmap: Replace g_memdup() by g_memdup2()
  softmmu: Replace g_memdup() by g_memdup2()
  hw/9pfs: Replace g_memdup() by g_memdup2()
  hw/acpi: Avoid truncating acpi_data_len() to 32-bit
  hw/acpi: Replace g_memdup() by g_memdup2()
  hw/core/machine: Replace g_memdup() by g_memdup2()
  hw/hppa/machine: Replace g_memdup() by g_memdup2()
  hw/i386/multiboot: Replace g_memdup() by g_memdup2()
  hw/net/eepro100: Replace g_memdup() by g_memdup2()
  hw/nvram/fw_cfg: Replace g_memdup() by g_memdup2()
  hw/scsi/mptsas: Replace g_memdup() by g_memdup2()
  hw/ppc/spapr_pci: Replace g_memdup() by g_memdup2()
  hw/rdma: Replace g_memdup() by g_memdup2()
  hw/vfio/pci: Replace g_memdup() by g_memdup2()
  hw/virtio: Replace g_memdup() by g_memdup2()
  net/colo: Replace g_memdup() by g_memdup2()
  ui/clipboard: Replace g_memdup() by g_memdup2()
  linux-user: Replace g_memdup() by g_memdup2()
  tests/unit: Replace g_memdup() by g_memdup2()
  tests/qtest: Replace g_memdup() by g_memdup2()
  target/arm: Replace g_memdup() by g_memdup2()
  target/ppc: Replace g_memdup() by g_memdup2()
  contrib: Replace g_memdup() by g_memdup2()
  checkpatch: Do not allow deprecated g_memdup()

 include/glib-compat.h       | 37 +++++++++++++++++++++++
 include/hw/hyperv/vmbus.h   |  3 --
 accel/tcg/cputlb.c          |  8 ++---
 block/qcow2-bitmap.c        |  2 +-
 contrib/plugins/lockstep.c  |  2 +-
 contrib/rdmacm-mux/main.c   | 10 +++----
 hw/9pfs/9p-synth.c          |  2 +-
 hw/9pfs/9p.c                |  2 +-
 hw/acpi/core.c              |  3 +-
 hw/arm/virt-acpi-build.c    |  2 +-
 hw/core/machine.c           |  4 +--
 hw/hppa/machine.c           |  8 ++---
 hw/hyperv/vmbus.c           | 59 -------------------------------------
 hw/i386/acpi-build.c        |  6 ++--
 hw/i386/multiboot.c         |  2 +-
 hw/net/eepro100.c           |  2 +-
 hw/net/virtio-net.c         |  3 +-
 hw/nvram/fw_cfg.c           |  9 +++---
 hw/ppc/spapr_pci.c          |  7 ++---
 hw/rdma/rdma_utils.c        |  2 +-
 hw/scsi/mptsas.c            |  5 ++--
 hw/vfio/pci.c               |  2 +-
 hw/virtio/virtio-crypto.c   |  6 ++--
 linux-user/syscall.c        |  2 +-
 linux-user/uaccess.c        |  2 +-
 net/colo.c                  |  4 +--
 qapi/qapi-clone-visitor.c   | 16 +++++-----
 qapi/qapi-visit-core.c      |  6 ++--
 softmmu/memory.c            |  2 +-
 softmmu/vl.c                |  2 +-
 target/arm/helper.c         |  6 ++--
 target/ppc/mmu-hash64.c     |  2 +-
 tests/qtest/libqos/ahci.c   |  6 ++--
 tests/qtest/libqos/qgraph.c |  2 +-
 tests/unit/ptimer-test.c    | 22 +++++++-------
 tests/unit/test-iov.c       | 26 ++++++++--------
 ui/clipboard.c              |  2 +-
 scripts/checkpatch.pl       |  5 ++++
 38 files changed, 138 insertions(+), 153 deletions(-)

-- 
2.31.1