This is a note to let you know that I've just added the patch titled
ARM: prctl: reject PR_SET_MDWE on pre-ARMv6
to the 6.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
arm-prctl-reject-pr_set_mdwe-on-pre-armv6.patch
and it can be found in the queue-6.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 166ce846dc5974a266f6c2a2896dbef5425a6f21 Mon Sep 17 00:00:00 2001
From: Zev Weiss <zev@xxxxxxxxxxxxxxxxx>
Date: Mon, 26 Feb 2024 17:35:42 -0800
Subject: ARM: prctl: reject PR_SET_MDWE on pre-ARMv6
From: Zev Weiss <zev@xxxxxxxxxxxxxxxxx>
commit 166ce846dc5974a266f6c2a2896dbef5425a6f21 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/arm/include/asm/mman.h | 14 ++++++++++++++
1 file changed, 14 insertions(+)
create mode 100644 arch/arm/include/asm/mman.h
--- /dev/null
+++ b/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 stable-queue which might be from zev@xxxxxxxxxxxxxxxxx are
queue-6.8/prctl-generalize-pr_set_mdwe-support-check-to-be-per-arch.patch
queue-6.8/arm-prctl-reject-pr_set_mdwe-on-pre-armv6.patch
