Commit a95ae27c authored by Thomas Garnier's avatar Thomas Garnier Committed by Ingo Molnar
Browse files

x86/mm: Enable KASLR for vmalloc memory regions 



Add vmalloc to the list of randomized memory regions.

The vmalloc memory region contains the allocation made through the vmalloc()
API. The allocations are done sequentially to prevent fragmentation and
each allocation address can easily be deduced especially from boot.

Signed-off-by: default avatarThomas Garnier <thgarnie@google.com>
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Cc: Alexander Kuleshov <kuleshovmail@gmail.com>
Cc: Alexander Popov <alpopov@ptsecurity.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Lv Zheng <lv.zheng@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: kernel-hardening@lists.openwall.com
Cc: linux-doc@vger.kernel.org
Link: http://lkml.kernel.org/r/1466556426-32664-8-git-send-email-keescook@chromium.org


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 021182e5

arch/x86/include/asm/kaslr.h

+1 −0
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ unsigned long kaslr_get_random_long(const char *purpose); 


#ifdef CONFIG_RANDOMIZE_MEMORY

extern unsigned long page_offset_base;

extern unsigned long vmalloc_base;



void kernel_randomize_memory(void);

#else

arch/x86/include/asm/pgtable_64_types.h

+11 −4
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ 


#ifndef __ASSEMBLY__

#include <linux/types.h>

#include <asm/kaslr.h>



/*

 * These are used to make use of C type-checking..
@@ -54,9 +55,15 @@ typedef struct { pteval_t pte; } pte_t; 


/* See Documentation/x86/x86_64/mm.txt for a description of the memory map. */

#define MAXMEM		_AC(__AC(1, UL) << MAX_PHYSMEM_BITS, UL)

#define VMALLOC_START    _AC(0xffffc90000000000, UL)

#define VMALLOC_END      _AC(0xffffe8ffffffffff, UL)

#define VMALLOC_SIZE_TB	_AC(32, UL)

#define __VMALLOC_BASE	_AC(0xffffc90000000000, UL)

#define VMEMMAP_START	_AC(0xffffea0000000000, UL)

#ifdef CONFIG_RANDOMIZE_MEMORY

#define VMALLOC_START	vmalloc_base

#else

#define VMALLOC_START	__VMALLOC_BASE

#endif /* CONFIG_RANDOMIZE_MEMORY */

#define VMALLOC_END	(VMALLOC_START + _AC((VMALLOC_SIZE_TB << 40) - 1, UL))

#define MODULES_VADDR    (__START_KERNEL_map + KERNEL_IMAGE_SIZE)

#define MODULES_END      _AC(0xffffffffff000000, UL)

#define MODULES_LEN   (MODULES_END - MODULES_VADDR)

arch/x86/mm/kaslr.c

+4 −1
Original line number Diff line number Diff line
@@ -44,11 +44,13 @@ 
 * ensure that this order is correct and won't be changed.

 */

static const unsigned long vaddr_start = __PAGE_OFFSET_BASE;

static const unsigned long vaddr_end = VMALLOC_START;

static const unsigned long vaddr_end = VMEMMAP_START;



/* Default values */

unsigned long page_offset_base = __PAGE_OFFSET_BASE;

EXPORT_SYMBOL(page_offset_base);

unsigned long vmalloc_base = __VMALLOC_BASE;

EXPORT_SYMBOL(vmalloc_base);



/*

 * Memory regions randomized by KASLR (except modules that use a separate logic
@@ -60,6 +62,7 @@ static __initdata struct kaslr_memory_region { 
	unsigned long size_tb;

} kaslr_regions[] = {

	{ &page_offset_base, 64/* Maximum */ },

	{ &vmalloc_base, VMALLOC_SIZE_TB },

};



/* Get size in bytes used by the memory region */

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