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[v3,26/28] target/ppc: Replace g_memdup() by g_memdup2()

Message ID 20210903174510.751630-27-philmd@redhat.com (mailing list archive)
State New, archived
Headers show
Series [v3,01/28] hw/hyperv/vmbus: Remove unused vmbus_load/save_req() | expand

Commit Message

Philippe Mathieu-Daudé Sept. 3, 2021, 5:45 p.m. UTC
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() wrapper.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 target/ppc/mmu-hash64.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

David Gibson Sept. 4, 2021, 3:38 a.m. UTC | #1
On Fri, Sep 03, 2021 at 07:45:08PM +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() wrapper.
> 
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

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

> ---
>  target/ppc/mmu-hash64.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/target/ppc/mmu-hash64.c b/target/ppc/mmu-hash64.c
> index 19832c4b46f..bc6f8748acb 100644
> --- a/target/ppc/mmu-hash64.c
> +++ b/target/ppc/mmu-hash64.c
> @@ -1122,7 +1122,7 @@ void ppc_hash64_init(PowerPCCPU *cpu)
>          return;
>      }
>  
> -    cpu->hash64_opts = g_memdup(pcc->hash64_opts, sizeof(*cpu->hash64_opts));
> +    cpu->hash64_opts = g_memdup2(pcc->hash64_opts, sizeof(*cpu->hash64_opts));
>  }
>  
>  void ppc_hash64_finalize(PowerPCCPU *cpu)
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Patch

diff --git a/target/ppc/mmu-hash64.c b/target/ppc/mmu-hash64.c
index 19832c4b46f..bc6f8748acb 100644
--- a/target/ppc/mmu-hash64.c
+++ b/target/ppc/mmu-hash64.c
@@ -1122,7 +1122,7 @@  void ppc_hash64_init(PowerPCCPU *cpu)
         return;
     }
 
-    cpu->hash64_opts = g_memdup(pcc->hash64_opts, sizeof(*cpu->hash64_opts));
+    cpu->hash64_opts = g_memdup2(pcc->hash64_opts, sizeof(*cpu->hash64_opts));
 }
 
 void ppc_hash64_finalize(PowerPCCPU *cpu)