Re: [PATCH 16/28] hw/ppc/spapr_pci: Replace g_memdup() by g_memdup2_qemu()

[David Gibson]

On Fri, Sep 03, 2021 at 01:06:50PM +0200, 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.
> 
> Replace g_memdup() by the safer g_memdup2_qemu() wrapper.
> 
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>


Acked-by: David Gibson <david@gibson.dropbear.id.au>

> ---
>  hw/ppc/spapr_pci.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> index 7430bd63142..79c0e8d4f98 100644
> --- a/hw/ppc/spapr_pci.c
> +++ b/hw/ppc/spapr_pci.c
> @@ -2201,10 +2201,10 @@ static int spapr_pci_post_load(void *opaque, int 
> version_id)
>      int i;
>  
>      for (i = 0; i < sphb->msi_devs_num; ++i) {
> -        key = g_memdup(&sphb->msi_devs[i].key,
> -                       sizeof(sphb->msi_devs[i].key));
> -        value = g_memdup(&sphb->msi_devs[i].value,
> -                         sizeof(sphb->msi_devs[i].value));
> +        key = g_memdup2_qemu(&sphb->msi_devs[i].key,
> +                             sizeof(sphb->msi_devs[i].key));
> +        value = g_memdup2_qemu(&sphb->msi_devs[i].value,
> +                               sizeof(sphb->msi_devs[i].value));
>          g_hash_table_insert(sphb->msi, key, value);
>      }
>      g_free(sphb->msi_devs);

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson

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