From a95ae27c2ee1cba5f4f6b9dea43ffe88252e79b1 Mon Sep 17 00:00:00 2001 From: Thomas Garnier Date: Tue, 21 Jun 2016 17:47:04 -0700 Subject: [PATCH] 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: Thomas Garnier Signed-off-by: Kees Cook Cc: Alexander Kuleshov Cc: Alexander Popov Cc: Andrew Morton Cc: Andy Lutomirski Cc: Aneesh Kumar K.V Cc: Baoquan He Cc: Boris Ostrovsky Cc: Borislav Petkov Cc: Borislav Petkov Cc: Brian Gerst Cc: Christian Borntraeger Cc: Dan Williams Cc: Dave Hansen Cc: Dave Young Cc: Denys Vlasenko Cc: Dmitry Vyukov Cc: H. Peter Anvin Cc: Jan Beulich Cc: Joerg Roedel Cc: Jonathan Corbet Cc: Josh Poimboeuf Cc: Juergen Gross Cc: Kirill A. Shutemov Cc: Linus Torvalds Cc: Lv Zheng Cc: Mark Salter Cc: Martin Schwidefsky Cc: Matt Fleming Cc: Peter Zijlstra Cc: Stephen Smalley Cc: Thomas Gleixner Cc: Toshi Kani Cc: Xiao Guangrong Cc: Yinghai Lu 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: Ingo Molnar --- arch/x86/include/asm/kaslr.h | 1 + arch/x86/include/asm/pgtable_64_types.h | 15 +++++++++++---- arch/x86/mm/kaslr.c | 5 ++++- 3 files changed, 16 insertions(+), 5 deletions(-) diff --git a/arch/x86/include/asm/kaslr.h b/arch/x86/include/asm/kaslr.h index 62b1b815a83a..2674ee3de748 100644 --- a/arch/x86/include/asm/kaslr.h +++ b/arch/x86/include/asm/kaslr.h @@ -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 diff --git a/arch/x86/include/asm/pgtable_64_types.h b/arch/x86/include/asm/pgtable_64_types.h index e6844dfb4471..6fdef9eef2d5 100644 --- a/arch/x86/include/asm/pgtable_64_types.h +++ b/arch/x86/include/asm/pgtable_64_types.h @@ -5,6 +5,7 @@ #ifndef __ASSEMBLY__ #include +#include /* * These are used to make use of C type-checking.. @@ -53,10 +54,16 @@ typedef struct { pteval_t pte; } pte_t; #define PGDIR_MASK (~(PGDIR_SIZE - 1)) /* 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 VMEMMAP_START _AC(0xffffea0000000000, UL) +#define MAXMEM _AC(__AC(1, UL) << MAX_PHYSMEM_BITS, 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) diff --git a/arch/x86/mm/kaslr.c b/arch/x86/mm/kaslr.c index 609ecf2b37ed..c939cfe1b516 100644 --- a/arch/x86/mm/kaslr.c +++ b/arch/x86/mm/kaslr.c @@ -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 */ -- 2.45.2