--- /dev/null
+From 95ee3aee92e32b90ff10f47cb6cfc414e1fd92b2 Mon Sep 17 00:00:00 2001
+From: Andrey Ryabinin <aryabinin@virtuozzo.com>
+Date: Wed, 15 Nov 2017 17:36:35 -0800
+Subject: [PATCH 127/231] x86/mm/kasan: Don't use vmemmap_populate() to
+ initialize shadow
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+CVE-2017-5754
+
+[ Note, this is a Git cherry-pick of the following commit:
+
+ d17a1d97dc20: ("x86/mm/kasan: don't use vmemmap_populate() to initialize shadow")
+
+ ... for easier x86 PTI code testing and back-porting. ]
+
+The KASAN shadow is currently mapped using vmemmap_populate() since that
+provides a semi-convenient way to map pages into init_top_pgt. However,
+since that no longer zeroes the mapped pages, it is not suitable for
+KASAN, which requires zeroed shadow memory.
+
+Add kasan_populate_shadow() interface and use it instead of
+vmemmap_populate(). Besides, this allows us to take advantage of
+gigantic pages and use them to populate the shadow, which should save us
+some memory wasted on page tables and reduce TLB pressure.
+
+Link: http://lkml.kernel.org/r/20171103185147.2688-2-pasha.tatashin@oracle.com
+Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
+Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
+Cc: Andy Lutomirski <luto@kernel.org>
+Cc: Steven Sistare <steven.sistare@oracle.com>
+Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
+Cc: Bob Picco <bob.picco@oracle.com>
+Cc: Michal Hocko <mhocko@suse.com>
+Cc: Alexander Potapenko <glider@google.com>
+Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
+Cc: Catalin Marinas <catalin.marinas@arm.com>
+Cc: Christian Borntraeger <borntraeger@de.ibm.com>
+Cc: David S. Miller <davem@davemloft.net>
+Cc: Dmitry Vyukov <dvyukov@google.com>
+Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
+Cc: "H. Peter Anvin" <hpa@zytor.com>
+Cc: Ingo Molnar <mingo@redhat.com>
+Cc: Mark Rutland <mark.rutland@arm.com>
+Cc: Matthew Wilcox <willy@infradead.org>
+Cc: Mel Gorman <mgorman@techsingularity.net>
+Cc: Michal Hocko <mhocko@kernel.org>
+Cc: Sam Ravnborg <sam@ravnborg.org>
+Cc: Thomas Gleixner <tglx@linutronix.de>
+Cc: Will Deacon <will.deacon@arm.com>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Ingo Molnar <mingo@kernel.org>
+(cherry picked from commit 2aeb07365bcd489620f71390a7d2031cd4dfb83e)
+Signed-off-by: Andy Whitcroft <apw@canonical.com>
+Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
+(cherry picked from commit f60ab0015a57d9fbf659b212d504682f069b0590)
+Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
+---
+ arch/x86/mm/kasan_init_64.c | 143 +++++++++++++++++++++++++++++++++++++++++---
+ arch/x86/Kconfig | 2 +-
+ 2 files changed, 137 insertions(+), 8 deletions(-)
+
+diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c
+index 464089f33e80..3d7341986e13 100644
+--- a/arch/x86/mm/kasan_init_64.c
++++ b/arch/x86/mm/kasan_init_64.c
+@@ -3,12 +3,14 @@
+ #include <linux/bootmem.h>
+ #include <linux/kasan.h>
+ #include <linux/kdebug.h>
++#include <linux/memblock.h>
+ #include <linux/mm.h>
+ #include <linux/sched.h>
+ #include <linux/sched/task.h>
+ #include <linux/vmalloc.h>
+
+ #include <asm/e820/types.h>
++#include <asm/pgalloc.h>
+ #include <asm/tlbflush.h>
+ #include <asm/sections.h>
+
+@@ -17,7 +19,134 @@ extern struct range pfn_mapped[E820_MAX_ENTRIES];
+
+ static p4d_t tmp_p4d_table[PTRS_PER_P4D] __initdata __aligned(PAGE_SIZE);
+
+-static int __init map_range(struct range *range)
++static __init void *early_alloc(size_t size, int nid)
++{
++ return memblock_virt_alloc_try_nid_nopanic(size, size,
++ __pa(MAX_DMA_ADDRESS), BOOTMEM_ALLOC_ACCESSIBLE, nid);
++}
++
++static void __init kasan_populate_pmd(pmd_t *pmd, unsigned long addr,
++ unsigned long end, int nid)
++{
++ pte_t *pte;
++
++ if (pmd_none(*pmd)) {
++ void *p;
++
++ if (boot_cpu_has(X86_FEATURE_PSE) &&
++ ((end - addr) == PMD_SIZE) &&
++ IS_ALIGNED(addr, PMD_SIZE)) {
++ p = early_alloc(PMD_SIZE, nid);
++ if (p && pmd_set_huge(pmd, __pa(p), PAGE_KERNEL))
++ return;
++ else if (p)
++ memblock_free(__pa(p), PMD_SIZE);
++ }
++
++ p = early_alloc(PAGE_SIZE, nid);
++ pmd_populate_kernel(&init_mm, pmd, p);
++ }
++
++ pte = pte_offset_kernel(pmd, addr);
++ do {
++ pte_t entry;
++ void *p;
++
++ if (!pte_none(*pte))
++ continue;
++
++ p = early_alloc(PAGE_SIZE, nid);
++ entry = pfn_pte(PFN_DOWN(__pa(p)), PAGE_KERNEL);
++ set_pte_at(&init_mm, addr, pte, entry);
++ } while (pte++, addr += PAGE_SIZE, addr != end);
++}
++
++static void __init kasan_populate_pud(pud_t *pud, unsigned long addr,
++ unsigned long end, int nid)
++{
++ pmd_t *pmd;
++ unsigned long next;
++
++ if (pud_none(*pud)) {
++ void *p;
++
++ if (boot_cpu_has(X86_FEATURE_GBPAGES) &&
++ ((end - addr) == PUD_SIZE) &&
++ IS_ALIGNED(addr, PUD_SIZE)) {
++ p = early_alloc(PUD_SIZE, nid);
++ if (p && pud_set_huge(pud, __pa(p), PAGE_KERNEL))
++ return;
++ else if (p)
++ memblock_free(__pa(p), PUD_SIZE);
++ }
++
++ p = early_alloc(PAGE_SIZE, nid);
++ pud_populate(&init_mm, pud, p);
++ }
++
++ pmd = pmd_offset(pud, addr);
++ do {
++ next = pmd_addr_end(addr, end);
++ if (!pmd_large(*pmd))
++ kasan_populate_pmd(pmd, addr, next, nid);
++ } while (pmd++, addr = next, addr != end);
++}
++
++static void __init kasan_populate_p4d(p4d_t *p4d, unsigned long addr,
++ unsigned long end, int nid)
++{
++ pud_t *pud;
++ unsigned long next;
++
++ if (p4d_none(*p4d)) {
++ void *p = early_alloc(PAGE_SIZE, nid);
++
++ p4d_populate(&init_mm, p4d, p);
++ }
++
++ pud = pud_offset(p4d, addr);
++ do {
++ next = pud_addr_end(addr, end);
++ if (!pud_large(*pud))
++ kasan_populate_pud(pud, addr, next, nid);
++ } while (pud++, addr = next, addr != end);
++}
++
++static void __init kasan_populate_pgd(pgd_t *pgd, unsigned long addr,
++ unsigned long end, int nid)
++{
++ void *p;
++ p4d_t *p4d;
++ unsigned long next;
++
++ if (pgd_none(*pgd)) {
++ p = early_alloc(PAGE_SIZE, nid);
++ pgd_populate(&init_mm, pgd, p);
++ }
++
++ p4d = p4d_offset(pgd, addr);
++ do {
++ next = p4d_addr_end(addr, end);
++ kasan_populate_p4d(p4d, addr, next, nid);
++ } while (p4d++, addr = next, addr != end);
++}
++
++static void __init kasan_populate_shadow(unsigned long addr, unsigned long end,
++ int nid)
++{
++ pgd_t *pgd;
++ unsigned long next;
++
++ addr = addr & PAGE_MASK;
++ end = round_up(end, PAGE_SIZE);
++ pgd = pgd_offset_k(addr);
++ do {
++ next = pgd_addr_end(addr, end);
++ kasan_populate_pgd(pgd, addr, next, nid);
++ } while (pgd++, addr = next, addr != end);
++}
++
++static void __init map_range(struct range *range)
+ {
+ unsigned long start;
+ unsigned long end;
+@@ -25,7 +154,7 @@ static int __init map_range(struct range *range)
+ start = (unsigned long)kasan_mem_to_shadow(pfn_to_kaddr(range->start));
+ end = (unsigned long)kasan_mem_to_shadow(pfn_to_kaddr(range->end));
+
+- return vmemmap_populate(start, end, NUMA_NO_NODE);
++ kasan_populate_shadow(start, end, early_pfn_to_nid(range->start));
+ }
+
+ static void __init clear_pgds(unsigned long start,
+@@ -188,16 +317,16 @@ void __init kasan_init(void)
+ if (pfn_mapped[i].end == 0)
+ break;
+
+- if (map_range(&pfn_mapped[i]))
+- panic("kasan: unable to allocate shadow!");
++ map_range(&pfn_mapped[i]);
+ }
++
+ kasan_populate_zero_shadow(
+ kasan_mem_to_shadow((void *)PAGE_OFFSET + MAXMEM),
+ kasan_mem_to_shadow((void *)__START_KERNEL_map));
+
+- vmemmap_populate((unsigned long)kasan_mem_to_shadow(_stext),
+- (unsigned long)kasan_mem_to_shadow(_end),
+- NUMA_NO_NODE);
++ kasan_populate_shadow((unsigned long)kasan_mem_to_shadow(_stext),
++ (unsigned long)kasan_mem_to_shadow(_end),
++ early_pfn_to_nid(__pa(_stext)));
+
+ kasan_populate_zero_shadow(kasan_mem_to_shadow((void *)MODULES_END),
+ (void *)KASAN_SHADOW_END);
+diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
+index 67d07802ae95..8b5499bb24bb 100644
+--- a/arch/x86/Kconfig
++++ b/arch/x86/Kconfig
+@@ -106,7 +106,7 @@ config X86
+ select HAVE_ARCH_AUDITSYSCALL
+ select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
+ select HAVE_ARCH_JUMP_LABEL
+- select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
++ select HAVE_ARCH_KASAN if X86_64
+ select HAVE_ARCH_KGDB
+ select HAVE_ARCH_KMEMCHECK
+ select HAVE_ARCH_MMAP_RND_BITS if MMU
+--
+2.14.2
+
projects / pve-kernel.git / blobdiff