From: Bingwu Zhang <xtex@envs.net>
To: Huacai Chen <chenhuacai@kernel.org>,
WANG Xuerui <kernel@xen0n.name>, Guo Ren <guoren@kernel.org>,
Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: loongarch@lists.linux.dev, linux-kernel@vger.kernel.org,
Bingwu Zhang <xtex@astrafall.org>
Subject: [PATCH] LoongArch: Increase default mmap randomization bits
Date: Sun, 29 Mar 2026 06:59:17 +0800 [thread overview]
Message-ID: <20260328225916.51802-2-xtex@envs.net> (raw)
From: Bingwu Zhang <xtex@astrafall.org>
Increase default mmap randomization bits from 12 to 18 on 64-bit
platforms for better strength.
The original default, 12, means that ASLR offset has only (1 << 12) =
4096 possibilities. On average, it can be brute-forced in 2048 attempts.
If a service is configured to restart automatically or can be started
easily (e.g. execve a suid program), then trying for 4k times can be
done in one day even when each attempt takes 20s.
Increasing it to 18 makes brute-force much more difficult and leaves
more time for operators to find out attacks.
On 64-bit platforms, virtual address space is cheap, so the
randomization bits can be increased safely without disturbing userland
much and security comes first instead of availability.
Fixes: fa96b57c1490 ("LoongArch: Add build infrastructure")
Signed-off-by: Bingwu Zhang <xtex@astrafall.org>
---
arch/loongarch/Kconfig | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
index 92068ff38685..b47c4e4ecbb7 100644
--- a/arch/loongarch/Kconfig
+++ b/arch/loongarch/Kconfig
@@ -740,9 +740,11 @@ config MMU
default y
config ARCH_MMAP_RND_BITS_MIN
+ default 18 if 64BIT
default 12
config ARCH_MMAP_RND_BITS_MAX
+ default 32 if 64BIT
default 18
config ARCH_SUPPORTS_UPROBES
base-commit: be762d8b6dd7efacb61937d20f8475db8f207655
--
2.52.0
next reply other threads:[~2026-03-28 22:59 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-28 22:59 Bingwu Zhang [this message]
2026-03-29 3:48 ` [PATCH] LoongArch: Increase default mmap randomization bits Huacai Chen
2026-04-12 3:49 ` Bingwu Zhang
2026-04-12 12:24 ` Huacai Chen
2026-04-12 12:32 ` Xi Ruoyao
2026-04-12 12:36 ` Huacai Chen
2026-04-12 12:37 ` Xi Ruoyao
2026-04-12 12:42 ` Huacai Chen
2026-04-13 2:05 ` xtex
2026-04-13 2:05 ` xtex
2026-04-13 2:38 ` Huacai Chen
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