This is a note to let you know that I've just added the patch titled
x86/elf: Remove the unnecessary ADDR_NO_RANDOMIZE checks
to the 4.12-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:
x86-elf-remove-the-unnecessary-addr_no_randomize-checks.patch
and it can be found in the queue-4.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 01578e36163cdd0e4fd61d9976de15f13364e26d Mon Sep 17 00:00:00 2001
From: Oleg Nesterov <oleg@xxxxxxxxxx>
Date: Tue, 15 Aug 2017 17:40:11 +0200
Subject: x86/elf: Remove the unnecessary ADDR_NO_RANDOMIZE checks
From: Oleg Nesterov <oleg@xxxxxxxxxx>
commit 01578e36163cdd0e4fd61d9976de15f13364e26d upstream.
The ADDR_NO_RANDOMIZE checks in stack_maxrandom_size() and
randomize_stack_top() are not required.
PF_RANDOMIZE is set by load_elf_binary() only if ADDR_NO_RANDOMIZE is not
set, no need to re-check after that.
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Dmitry Safonov <dsafonov@xxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/20170815154011.GB1076@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/mm/mmap.c | 3 +--
fs/binfmt_elf.c | 3 +--
2 files changed, 2 insertions(+), 4 deletions(-)
--- a/arch/x86/mm/mmap.c
+++ b/arch/x86/mm/mmap.c
@@ -50,8 +50,7 @@ unsigned long tasksize_64bit(void)
static unsigned long stack_maxrandom_size(unsigned long task_size)
{
unsigned long max = 0;
- if ((current->flags & PF_RANDOMIZE) &&
- !(current->personality & ADDR_NO_RANDOMIZE)) {
+ if (current->flags & PF_RANDOMIZE) {
max = (-1UL) & __STACK_RND_MASK(task_size == tasksize_32bit());
max <<= PAGE_SHIFT;
}
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -666,8 +666,7 @@ static unsigned long randomize_stack_top
{
unsigned long random_variable = 0;
- if ((current->flags & PF_RANDOMIZE) &&
- !(current->personality & ADDR_NO_RANDOMIZE)) {
+ if (current->flags & PF_RANDOMIZE) {
random_variable = get_random_long();
random_variable &= STACK_RND_MASK;
random_variable <<= PAGE_SHIFT;
Patches currently in stable-queue which might be from oleg@xxxxxxxxxx are
queue-4.12/x86-elf-remove-the-unnecessary-addr_no_randomize-checks.patch
queue-4.12/mm-fix-double-mmap_sem-unlock-on-mmf_unstable-enforced-sigbus.patch
queue-4.12/x86-fix-norandmaps-addr_no_randomize.patch