This is a note to let you know that I've just added the patch titled
arm64: avoid overflow in VA_START and PAGE_OFFSET
to the 4.9-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:
arm64-avoid-overflow-in-va_start-and-page_offset.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 82cd588052815eb4146f9f7c5347ca5e32c56360 Mon Sep 17 00:00:00 2001
From: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Date: Thu, 3 Aug 2017 11:03:58 -0700
Subject: arm64: avoid overflow in VA_START and PAGE_OFFSET
From: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
commit 82cd588052815eb4146f9f7c5347ca5e32c56360 upstream.
The bitmask used to define these values produces overflow, as seen by
this compiler warning:
arch/arm64/kernel/head.S:47:8: warning:
integer overflow in preprocessor expression
#elif (PAGE_OFFSET & 0x1fffff) != 0
^~~~~~~~~~~
arch/arm64/include/asm/memory.h:52:46: note:
expanded from macro 'PAGE_OFFSET'
#define PAGE_OFFSET (UL(0xffffffffffffffff) << (VA_BITS -
1))
~~~~~~~~~~~~~~~~~~ ^
It would be preferrable to use GENMASK_ULL() instead, but it's not set
up to be used from assembly (the UL() macro token pastes UL suffixes
when not included in assembly sources).
Suggested-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Suggested-by: Yury Norov <ynorov@xxxxxxxxxxxxxxxxxx>
Suggested-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Signed-off-by: Will Deacon <will.deacon@xxxxxxx>
Cc: Nathan Chancellor <natechancellor@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/arm64/include/asm/memory.h | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -64,8 +64,10 @@
* TASK_UNMAPPED_BASE - the lower boundary of the mmap VM area.
*/
#define VA_BITS (CONFIG_ARM64_VA_BITS)
-#define VA_START (UL(0xffffffffffffffff) << VA_BITS)
-#define PAGE_OFFSET (UL(0xffffffffffffffff) << (VA_BITS - 1))
+#define VA_START (UL(0xffffffffffffffff) - \
+ (UL(1) << VA_BITS) + 1)
+#define PAGE_OFFSET (UL(0xffffffffffffffff) - \
+ (UL(1) << (VA_BITS - 1)) + 1)
#define KIMAGE_VADDR (MODULES_END)
#define MODULES_END (MODULES_VADDR + MODULES_VSIZE)
#define MODULES_VADDR (VA_START + KASAN_SHADOW_SIZE)
Patches currently in stable-queue which might be from ndesaulniers@xxxxxxxxxx are
queue-4.9/arm64-avoid-overflow-in-va_start-and-page_offset.patch
queue-4.9/netfilter-nf_nat_h323-fix-logical-not-parentheses-warning.patch