Re: [PATCH] binfmt_elf: randomize PIE binaries (2nd try)

["Jesper Juhl" <jesper.juhl@gmail.com>]

On 20/10/06, Marcus Meissner <meissner@suse.de> wrote:
> Randomizes -pie compiled binaries from PAGE_SIZE up to
> ELF_ET_DYN_BASE.
>
> 0 -> PAGE_SIZE is excluded to allow NULL ptr accesses
> to fail.
>
> Signed-off-by: Marcus Meissner <meissner@suse.de>
>
> ----
>  binfmt_elf.c |    8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
>
> --- linux-2.6.18/fs/binfmt_elf.c.xx     2006-10-20 10:42:03.000000000 +0200
> +++ linux-2.6.18/fs/binfmt_elf.c        2006-10-20 10:51:27.000000000 +0200
> @@ -856,7 +856,13 @@
>                          * default mmap base, as well as whatever program they
>                          * might try to exec.  This is because the brk will
>                          * follow the loader, and is not movable.  */
> -                       load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
> +                       if (current->flags & PF_RANDOMIZE)
> +                               load_bias = randomize_range(PAGE_SIZE,
> +                                                           ELF_ET_DYN_BASE,
> +                                                           0);

How about putting the two lines above on one line?  ^^^^^

> +                                                           ELF_ET_DYN_BASE, 0);


--
Jesper Juhl <jesper.juhl@gmail.com>
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