From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:56790 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753429AbdHTTB0 (ORCPT ); Sun, 20 Aug 2017 15:01:26 -0400 Subject: Patch "x86: Fix norandmaps/ADDR_NO_RANDOMIZE" has been added to the 4.12-stable tree To: oleg@redhat.com, akpm@linux-foundation.org, bp@suse.de, dsafonov@virtuozzo.com, gorcunov@openvz.org, gregkh@linuxfoundation.org, kirill.shutemov@linux.intel.com, luto@amacapital.net, tglx@linutronix.de, torvalds@linux-foundation.org Cc: , From: Date: Sun, 20 Aug 2017 12:01:21 -0700 Message-ID: <150325568112885@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled x86: Fix norandmaps/ADDR_NO_RANDOMIZE 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-fix-norandmaps-addr_no_randomize.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 know about it. >>From 47ac5484fd961420e5ec0bb5b972fde381f57365 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Tue, 15 Aug 2017 17:39:52 +0200 Subject: x86: Fix norandmaps/ADDR_NO_RANDOMIZE From: Oleg Nesterov commit 47ac5484fd961420e5ec0bb5b972fde381f57365 upstream. Documentation/admin-guide/kernel-parameters.txt says: norandmaps Don't use address space randomization. Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space but it doesn't work because arch_rnd() which is used to randomize mm->mmap_base returns a random value unconditionally. And as Kirill pointed out, ADDR_NO_RANDOMIZE is broken by the same reason. Just shift the PF_RANDOMIZE check from arch_mmap_rnd() to arch_rnd(). Fixes: 1b028f784e8c ("x86/mm: Introduce mmap_compat_base() for 32-bit mmap()") Signed-off-by: Oleg Nesterov Signed-off-by: Thomas Gleixner Acked-by: Kirill A. Shutemov Acked-by: Cyrill Gorcunov Reviewed-by: Dmitry Safonov Cc: Andy Lutomirski Cc: Andrew Morton Cc: Borislav Petkov Cc: Linus Torvalds Link: http://lkml.kernel.org/r/20170815153952.GA1076@redhat.com Signed-off-by: Greg Kroah-Hartman --- arch/x86/mm/mmap.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/arch/x86/mm/mmap.c +++ b/arch/x86/mm/mmap.c @@ -82,13 +82,13 @@ static int mmap_is_legacy(void) static unsigned long arch_rnd(unsigned int rndbits) { + if (!(current->flags & PF_RANDOMIZE)) + return 0; return (get_random_long() & ((1UL << rndbits) - 1)) << PAGE_SHIFT; } unsigned long arch_mmap_rnd(void) { - if (!(current->flags & PF_RANDOMIZE)) - return 0; return arch_rnd(mmap_is_ia32() ? mmap32_rnd_bits : mmap64_rnd_bits); } Patches currently in stable-queue which might be from oleg@redhat.com 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