Re: [PATCH] libxl: Fix format string abuses / vulnerabilities

[Gianni Tedesco <gianni.tedesco@citrix.com>]

On Wed, 2010-10-27 at 14:17 +0100, Ian Jackson wrote:
> There are a few places where libxl__xs_write is passed a variable
> value to write to xenstore, but the semantics are that the first char*
> is a format string.  So use "%s".
> 
> This fixes the following errors reported by some newer compilers:
>  libxl.c: In function "libxl_create_cpupool":
>  libxl.c:3981: error: format not a string literal and no format arguments
>  libxl.c:3983: error: format not a string literal and no format arguments
>  libxl.c: In function "libxl_cpupool_movedomain":
>  libxl.c:4095: error: format not a string literal and no format arguments
> 
> Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
> 
> diff -r 28a160746815 tools/libxl/libxl.c
> --- a/tools/libxl/libxl.c	Wed Oct 27 12:24:28 2010 +0100
> +++ b/tools/libxl/libxl.c	Wed Oct 27 13:38:30 2010 +0100
> @@ -3977,10 +3977,12 @@ int libxl_create_cpupool(libxl_ctx *ctx,
>          t = xs_transaction_start(ctx->xsh);
>  
>          xs_mkdir(ctx->xsh, t, libxl__sprintf(&gc, "/local/pool/%d", *poolid));
> -        libxl__xs_write(&gc, t, libxl__sprintf(&gc, "/local/pool/%d/uuid", *poolid),
> -                 uuid_string);
> -        libxl__xs_write(&gc, t, libxl__sprintf(&gc, "/local/pool/%d/name", *poolid),
> -                 name);
> +        libxl__xs_write(&gc, t,
> +                        libxl__sprintf(&gc, "/local/pool/%d/uuid", *poolid),
> +                        "%s", uuid_string);
> +        libxl__xs_write(&gc, t,
> +                        libxl__sprintf(&gc, "/local/pool/%d/name", *poolid),
> +                        "%s", name);
>  
>          if (xs_transaction_end(ctx->xsh, t, 0) || (errno != EAGAIN))
>              return 0;
> @@ -4092,7 +4094,8 @@ int libxl_cpupool_movedomain(libxl_ctx *
>          if (!vm_path)
>              break;
>  
> -        libxl__xs_write(&gc, t, libxl__sprintf(&gc, "%s/pool_name", vm_path), poolname);
> +        libxl__xs_write(&gc, t, libxl__sprintf(&gc, "%s/pool_name", vm_path),
> +                        "%s", poolname);
>  

Good lord!

Ack.

Gianni