This is a note to let you know that I've just added the patch titled

    x86 get_unmapped_area(): use proper mmap base for bottom-up direction

to the 3.10-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-get_unmapped_area-use-proper-mmap-base-for-bottom-up-direction.patch
and it can be found in the queue-3.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.


>From df54d6fa54275ce59660453e29d1228c2b45a826 Mon Sep 17 00:00:00 2001
From: Radu Caragea <[email protected]>
Date: Tue, 13 Aug 2013 16:00:59 -0700
Subject: x86 get_unmapped_area(): use proper mmap base for bottom-up direction

From: Radu Caragea <[email protected]>

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 <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Reviewed-by: Rik van Riel <[email protected]>
Acked-by: Ingo Molnar <[email protected]>
Cc: Adrian Sendroiu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 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(-)

--- 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
                                *begin = new_begin;
                }
        } else {
-               *begin = TASK_UNMAPPED_BASE;
+               *begin = mmap_legacy_base();
                *end = TASK_SIZE;
        }
 }
--- 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;
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -314,6 +314,7 @@ struct nsproxy;
 struct user_namespace;
 
 #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,


Patches currently in stable-queue which might be from [email protected] are

queue-3.10/x86-get_unmapped_area-use-proper-mmap-base-for-bottom-up-direction.patch
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