Re: [PATCH 26/28] target/ppc: Replace g_memdup() by g_memdup2_qemu()

[David Gibson]

On Fri, Sep 03, 2021 at 01:07:00PM +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>

> ---
>  target/ppc/mmu-hash64.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/target/ppc/mmu-hash64.c b/target/ppc/mmu-hash64.c
> index 19832c4b46f..2ee6025a406 100644
> --- a/target/ppc/mmu-hash64.c
> +++ b/target/ppc/mmu-hash64.c
> @@ -1122,7 +1122,8 @@ void ppc_hash64_init(PowerPCCPU *cpu)
>          return;
>      }
>  
> -    cpu->hash64_opts = g_memdup(pcc->hash64_opts, sizeof(*cpu->hash64_opts));
> +    cpu->hash64_opts = g_memdup2_qemu(pcc->hash64_opts,
> +                                      sizeof(*cpu->hash64_opts));
>  }
>  
>  void ppc_hash64_finalize(PowerPCCPU *cpu)

-- 
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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