Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756356Ab3HPWjE (ORCPT ); Fri, 16 Aug 2013 18:39:04 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:51564 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756264Ab3HPWiy (ORCPT ); Fri, 16 Aug 2013 18:38:54 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Michel Lespinasse , Oleg Nesterov , Adrian Sendroiu , Andrew Morton , Linus Torvalds , Kamal Mostafa Subject: [PATCH 121/133] x86 get_unmapped_area(): use proper mmap base for bottom-up direction Date: Fri, 16 Aug 2013 15:34:23 -0700 Message-Id: <1376692475-28413-122-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1376692475-28413-1-git-send-email-kamal@canonical.com> References: <1376692475-28413-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2470 Lines: 72 3.8.13.7 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Radu Caragea commit df54d6fa54275ce59660453e29d1228c2b45a826 upstream. When the stack is set to unlimited, the bottomup direction is used for mmap-ings but the mmap_base is not used and thus effectively renders ASLR for mmapings along with PIE useless. Cc: Michel Lespinasse Cc: Oleg Nesterov Reviewed-by: Rik van Riel Acked-by: Ingo Molnar Cc: Adrian Sendroiu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Kamal Mostafa --- arch/x86/kernel/sys_x86_64.c | 2 +- arch/x86/mm/mmap.c | 2 +- include/linux/sched.h | 1 + 3 files changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/sys_x86_64.c b/arch/x86/kernel/sys_x86_64.c index 97ef74b..af46e18 100644 --- a/arch/x86/kernel/sys_x86_64.c +++ b/arch/x86/kernel/sys_x86_64.c @@ -101,7 +101,7 @@ static void find_start_end(unsigned long flags, unsigned long *begin, *begin = new_begin; } } else { - *begin = TASK_UNMAPPED_BASE; + *begin = mmap_legacy_base(); *end = TASK_SIZE; } } diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c index 845df68..c1af323 100644 --- a/arch/x86/mm/mmap.c +++ b/arch/x86/mm/mmap.c @@ -98,7 +98,7 @@ static unsigned long mmap_base(void) * Bottom-up (legacy) layout on X86_32 did not support randomization, X86_64 * does, but not when emulating X86_32 */ -static unsigned long mmap_legacy_base(void) +unsigned long mmap_legacy_base(void) { if (mmap_is_ia32()) return TASK_UNMAPPED_BASE; diff --git a/include/linux/sched.h b/include/linux/sched.h index caa76ae..9d96429 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -360,6 +360,7 @@ extern int sysctl_max_map_count; #include #ifdef CONFIG_MMU +extern unsigned long mmap_legacy_base(void); extern void arch_pick_mmap_layout(struct mm_struct *mm); extern unsigned long arch_get_unmapped_area(struct file *, unsigned long, unsigned long, -- 1.8.1.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/