Re: [PATCH] x86/mm: Fix personality(ADDR_NO_RANDOMIZE)

From: Cyrill Gorcunov
Date: Mon Aug 14 2017 - 12:14:00 EST


On Mon, Aug 14, 2017 at 06:57:19PM +0300, Kirill A. Shutemov wrote:
> In v4.12, during rework of infrastructure around mmap_base, disable-ASLR
> personality flag got accidentally broken.
>
> Let's make it work again.
>
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
> Fixes: 1b028f784e8c ("x86/mm: Introduce mmap_compat_base() for 32-bit mmap()")
> Cc: stable <stable@xxxxxxxxxxxxxxx> [4.12+]
> ---
> arch/x86/mm/mmap.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c
> index 229d04a83f85..779bdbe5e424 100644
> --- a/arch/x86/mm/mmap.c
> +++ b/arch/x86/mm/mmap.c
> @@ -127,6 +127,8 @@ static unsigned long mmap_legacy_base(unsigned long rnd,
> static void arch_pick_mmap_base(unsigned long *base, unsigned long *legacy_base,
> unsigned long random_factor, unsigned long task_size)
> {
> + if (!(current->flags & PF_RANDOMIZE))
> + random_factor = 0;
> *legacy_base = mmap_legacy_base(random_factor, task_size);
> if (mmap_is_legacy())
> *base = *legacy_base;

Didn't Oleg's patch does the same?

https://patchwork.kernel.org/patch/9832697/

for some reason it's not yet merged.