Re: [PATCH 09/28] hw/acpi: Replace g_memdup() by g_memdup2_qemu()

[Igor Mammedov]

On Fri,  3 Sep 2021 13:06:43 +0200
Philippe Mathieu-Daudé <philmd@redhat.com> 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.
> 
> Replace g_memdup() by the safer g_memdup2_qemu() wrapper.
> 
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Acked-by: Igor Mammedov <imammedo@redhat.com>


> ---
>  hw/acpi/core.c       | 3 ++-
>  hw/i386/acpi-build.c | 2 +-
>  2 files changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/acpi/core.c b/hw/acpi/core.c
> index 1e004d0078d..9dd2cf09a0b 100644
> --- a/hw/acpi/core.c
> +++ b/hw/acpi/core.c
> @@ -637,7 +637,8 @@ void acpi_pm1_cnt_init(ACPIREGS *ar, MemoryRegion *parent,
>          suspend[3] = 1 | ((!disable_s3) << 7);
>          suspend[4] = s4_val | ((!disable_s4) << 7);
>  
> -        fw_cfg_add_file(fw_cfg, "etc/system-states", g_memdup(suspend, 6), 
> 6);
> +        fw_cfg_add_file(fw_cfg, "etc/system-states",
> +                        g_memdup2_qemu(suspend, 6), 6);
>      }
>  }
>  
> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index aa269914b49..54494ca1f65 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -2785,7 +2785,7 @@ void acpi_setup(void)
>           */
>          unsigned rsdp_size = acpi_data_len(tables.rsdp);
>  
> -        build_state->rsdp = g_memdup(tables.rsdp->data, rsdp_size);
> +        build_state->rsdp = g_memdup2_qemu(tables.rsdp->data, rsdp_size);
>          fw_cfg_add_file_callback(x86ms->fw_cfg, ACPI_BUILD_RSDP_FILE,
>                                   acpi_build_update, NULL, build_state,
>                                   build_state->rsdp, rsdp_size, true);