Patch "parisc: Hide virtual kernel memory layout" has been added to the 4.15-stable tree

Patch "parisc: Hide virtual kernel memory layout" has been added to the 4.15-stable tree

[gregkh]

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

    parisc: Hide virtual kernel memory layout

to the 4.15-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:
     parisc-hide-virtual-kernel-memory-layout.patch
and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From fd8d0ca2563151204f3fe555dc8ca4bcfe8677a3 Mon Sep 17 00:00:00 2001
From: Helge Deller <deller@gmx.de>
Date: Fri, 12 Jan 2018 22:57:15 +0100
Subject: parisc: Hide virtual kernel memory layout

From: Helge Deller <deller@gmx.de>

commit fd8d0ca2563151204f3fe555dc8ca4bcfe8677a3 upstream.

For security reasons do not expose the virtual kernel memory layout to
userspace.

Signed-off-by: Helge Deller <deller@gmx.de>
Suggested-by: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org # 4.15
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/parisc/mm/init.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

--- a/arch/parisc/mm/init.c
+++ b/arch/parisc/mm/init.c
@@ -629,7 +629,12 @@ void __init mem_init(void)
 #endif
 
 	mem_init_print_info(NULL);
-#ifdef CONFIG_DEBUG_KERNEL /* double-sanity-check paranoia */
+
+#if 0
+	/*
+	 * Do not expose the virtual kernel memory layout to userspace.
+	 * But keep code for debugging purposes.
+	 */
 	printk("virtual kernel memory layout:\n"
 	       "    vmalloc : 0x%px - 0x%px   (%4ld MB)\n"
 	       "    memory  : 0x%px - 0x%px   (%4ld MB)\n"


Patches currently in stable-queue which might be from deller@gmx.de are

queue-4.15/parisc-hide-virtual-kernel-memory-layout.patch
queue-4.15/parisc-use-cr16-interval-timers-unconditionally-on-qemu.patch
queue-4.15/parisc-fix-ordering-of-cache-and-tlb-flushes.patch
queue-4.15/parisc-reduce-irq-overhead-when-run-in-qemu.patch