The patch titled
Subject: ARM: prctl: reject PR_SET_MDWE on pre-ARMv6
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
arm-prctl-reject-pr_set_mdwe-on-pre-armv6.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/arm-prctl-reject-pr_set_mdwe-on-pre-armv6.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Zev Weiss <zev@xxxxxxxxxxxxxxxxx>
Subject: ARM: prctl: reject PR_SET_MDWE on pre-ARMv6
Date: Mon, 26 Feb 2024 17:35:42 -0800
On v5 and lower CPUs we can't provide MDWE protection, so ensure we fail
any attempt to enable it via prctl(PR_SET_MDWE).
Previously such an attempt would misleadingly succeed, leading to any
subsequent mmap(PROT_READ|PROT_WRITE) or execve() failing unconditionally
(the latter somewhat violently via force_fatal_sig(SIGSEGV) due to
READ_IMPLIES_EXEC).
Link: https://lkml.kernel.org/r/20240227013546.15769-6-zev@xxxxxxxxxxxxxxxxx
Signed-off-by: Zev Weiss <zev@xxxxxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> [6.3+]
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Florent Revest <revest@xxxxxxxxxxxx>
Cc: Helge Deller <deller@xxxxxx>
Cc: "James E.J. Bottomley" <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
Cc: Josh Triplett <josh@xxxxxxxxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Miguel Ojeda <ojeda@xxxxxxxxxx>
Cc: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Ondrej Mosnacek <omosnace@xxxxxxxxxx>
Cc: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx>
Cc: Russell King (Oracle) <linux@xxxxxxxxxxxxxxx>
Cc: Sam James <sam@xxxxxxxxxx>
Cc: Stefan Roesch <shr@xxxxxxxxxxxx>
Cc: Yang Shi <yang@xxxxxxxxxxxxxxxxxxxxxx>
Cc: Yin Fengwei <fengwei.yin@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/arm/include/asm/mman.h | 14 ++++++++++++++
1 file changed, 14 insertions(+)
--- /dev/null
+++ a/arch/arm/include/asm/mman.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_MMAN_H__
+#define __ASM_MMAN_H__
+
+#include <asm/system_info.h>
+#include <uapi/asm/mman.h>
+
+static inline bool arch_memory_deny_write_exec_supported(void)
+{
+ return cpu_architecture() >= CPU_ARCH_ARMv6;
+}
+#define arch_memory_deny_write_exec_supported arch_memory_deny_write_exec_supported
+
+#endif /* __ASM_MMAN_H__ */
_
Patches currently in -mm which might be from zev@xxxxxxxxxxxxxxxxx are
prctl-generalize-pr_set_mdwe-support-check-to-be-per-arch.patch
arm-prctl-reject-pr_set_mdwe-on-pre-armv6.patch
