Re: [PATCH v2 00/30] glib: Replace g_memdup() by g_memdup2()

[Philippe Mathieu-Daudé]

On 9/3/21 7:39 PM, Philippe Mathieu-Daudé wrote:
> 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)
> 
> Philippe Mathieu-Daudé (30):
>   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()
>   RFC hw/virtio: Replace g_memdup() by g_memdup2()
>   net/colo: Replace g_memdup() by g_memdup2()
>   RFC ui/clipboard: Replace g_memdup() by g_memdup2()
>   RFC 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()
>   f
>   test

I figured too late I was not placed in the correct commit,
please disregard this incomplete series...