kasan: arm64: fix pcpu_page_first_chunk crash with KASAN_VMALLOC

With KASAN_VMALLOC and NEED_PER_CPU_PAGE_FIRST_CHUNK the kernel crashes:

  Unable to handle kernel paging request at virtual address ffff7000028f2000
  ...
  swapper pgtable: 64k pages, 48-bit VAs, pgdp=0000000042440000
  [ffff7000028f2000] pgd=000000063e7c0003, p4d=000000063e7c0003, pud=000000063e7c0003, pmd=000000063e7b0003, pte=0000000000000000
  Internal error: Oops: 96000007 [#1] PREEMPT SMP
  Modules linked in:
  CPU: 0 PID: 0 Comm: swapper Not tainted 5.13.0-rc4-00003-gc6e6e28f3f30-dirty #62
  Hardware name: linux,dummy-virt (DT)
  pstate: 200000c5 (nzCv daIF -PAN -UAO -TCO BTYPE=--)
  pc : kasan_check_range+0x90/0x1a0
  lr : memcpy+0x88/0xf4
  sp : ffff80001378fe20
  ...
  Call trace:
   kasan_check_range+0x90/0x1a0
   pcpu_page_first_chunk+0x3f0/0x568
   setup_per_cpu_areas+0xb8/0x184
   start_kernel+0x8c/0x328

The vm area used in vm_area_register_early() has no kasan shadow memory,
Let's add a new kasan_populate_early_vm_area_shadow() function to
populate the vm area shadow memory to fix the issue.

[wangkefeng.wang@huawei.com: fix redefinition of 'kasan_populate_early_vm_area_shadow']
Link: https://lkml.kernel.org/r/20211011123211.3936196-1-wangkefeng.wang@huawei.com
Link: https://lkml.kernel.org/r/20210910053354.26721-4-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Marco Elver <elver@google.com>		[KASAN]
Acked-by: Andrey Konovalov <andreyknvl@gmail.com>	[KASAN]
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c
index 61b52a92b8b68b0d6a9d72bd816f6483bcb7c175..5b996ca4d99609a3b1588acca9d602fb1d0f8523 100644 (file)
--- a/arch/arm64/mm/kasan_init.c
+++ b/arch/arm64/mm/kasan_init.c
@@ -287,6 +287,22 @@ static void __init kasan_init_depth(void)
        init_task.kasan_depth = 0;
 }
 
+#ifdef CONFIG_KASAN_VMALLOC
+void __init kasan_populate_early_vm_area_shadow(void *start, unsigned long size)
+{
+       unsigned long shadow_start, shadow_end;
+
+       if (!is_vmalloc_or_module_addr(start))
+               return;
+
+       shadow_start = (unsigned long)kasan_mem_to_shadow(start);
+       shadow_start = ALIGN_DOWN(shadow_start, PAGE_SIZE);
+       shadow_end = (unsigned long)kasan_mem_to_shadow(start + size);
+       shadow_end = ALIGN(shadow_end, PAGE_SIZE);
+       kasan_map_populate(shadow_start, shadow_end, NUMA_NO_NODE);
+}
+#endif
+
 void __init kasan_init(void)
 {
        kasan_init_shadow();

diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index 736d7b458996df56f8cae8d8e27d9e0c056bbb03..65487a3b2a7116942b0a73301fefe521bf27ade6 100644 (file)
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -436,6 +436,8 @@ void kasan_release_vmalloc(unsigned long start, unsigned long end,
                           unsigned long free_region_start,
                           unsigned long free_region_end);
 
+void kasan_populate_early_vm_area_shadow(void *start, unsigned long size);
+
 #else /* CONFIG_KASAN_VMALLOC */
 
 static inline int kasan_populate_vmalloc(unsigned long start,
@@ -453,6 +455,10 @@ static inline void kasan_release_vmalloc(unsigned long start,
                                         unsigned long free_region_start,
                                         unsigned long free_region_end) {}
 
+static inline void kasan_populate_early_vm_area_shadow(void *start,
+                                                      unsigned long size)
+{ }
+
 #endif /* CONFIG_KASAN_VMALLOC */
 
 #if (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)) && \

diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c
index 8d95ee52d0194e1862f1410d6bb20d64b20d734d..4a4929b29a237f7fd3617817491d173ed7d205b0 100644 (file)
--- a/mm/kasan/shadow.c
+++ b/mm/kasan/shadow.c
@@ -254,6 +254,11 @@ core_initcall(kasan_memhotplug_init);
 
 #ifdef CONFIG_KASAN_VMALLOC
 
+void __init __weak kasan_populate_early_vm_area_shadow(void *start,
+                                                      unsigned long size)
+{
+}
+
 static int kasan_populate_vmalloc_pte(pte_t *ptep, unsigned long addr,
                                      void *unused)
 {

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 74da45a8beec0435495e8feb63dcb76d62ee722b..75fa100f542404f3b06b949e02dc3f79b1df548d 100644 (file)
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -2291,6 +2291,7 @@ void __init vm_area_register_early(struct vm_struct *vm, size_t align)
        vm->addr = (void *)addr;
        vm->next = *p;
        *p = vm;
+       kasan_populate_early_vm_area_shadow(vm->addr, vm->size);
 }
 
 static void vmap_init_free_space(void)