On Fri, 16 Feb 2024, Kees Cook wrote:
> In commit c1d171a00294 ("x86: randomize brk"), arch_randomize_brk() was
> defined to use a 32MB range (13 bits of entropy), but was never increased
> when moving to 64-bit. The default arch_randomize_brk() uses 32MB for
> 32-bit tasks, and 1GB (18 bits of entropy) for 64-bit tasks. Update
> x86_64 to match the entropy used by arm64 and other 64-bit architectures.
>
> Reported-by: [email protected]
> Closes:
> https://lore.kernel.org/linux-hardening/CA+2EKTVLvc8hDZc+2Yhwmus=dzoug5e4gv7aycbu0mpjtzz...@mail.gmail.com/
> Signed-off-by: Kees Cook <[email protected]>
Wow, this is a pretty aged code indeed.
Acked-by: Jiri Kosina <[email protected]>
Thanks,
--
Jiri Kosina
SUSE Labs
