Re: [RFC PATCH 1/2] Port KASAN Tests to KUnit

[Patricia Alfonso <trishalfonso@google.com>]

On Thu, Feb 27, 2020 at 6:19 AM Dmitry Vyukov <dvyukov@google.com> wrote:
>
> .On Thu, Feb 27, 2020 at 3:44 AM Patricia Alfonso
> <trishalfonso@google.com> wrote:
> >
> > Transfer all previous tests for KASAN to KUnit so they can be run
> > more easily. With proper KASAN integration into KUnit, developers can
> > run these tests with their other KUnit tests and see "pass" or "fail"
> > with the appropriate KASAN report instead of needing to parse each KASAN
> > report to test KASAN functionalities.
> >
> > Stack tests do not work in UML so those tests are protected inside an
> > "#if (CONFIG_KASAN_STACK == 1)" so this only runs if stack
> > instrumentation is enabled.
> >
> > Signed-off-by: Patricia Alfonso <trishalfonso@google.com>
> > ---
> > The KUnit version of these tests could be in addition to the existing
> > tests if that is preferred.
> >
> >  lib/Kconfig.kasan |   2 +-
> >  lib/test_kasan.c  | 352 +++++++++++++++++++++-------------------------
> >  2 files changed, 161 insertions(+), 193 deletions(-)
> >
> > diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan
> > index 5b54f3c9a741..f8cc9ed60677 100644
> > --- a/lib/Kconfig.kasan
> > +++ b/lib/Kconfig.kasan
> > @@ -160,7 +160,7 @@ config KASAN_VMALLOC
> >
> >  config TEST_KASAN
> >         tristate "Module for testing KASAN for bug detection"
> > -       depends on m && KASAN
> > +       depends on KASAN && KUNIT
> >         help
> >           This is a test module doing various nasty things like
> >           out of bounds accesses, use after free. It is useful for testing
> > diff --git a/lib/test_kasan.c b/lib/test_kasan.c
> > index 3872d250ed2c..988650387a2a 100644
> > --- a/lib/test_kasan.c
> > +++ b/lib/test_kasan.c
> > @@ -23,17 +23,18 @@
> >
> >  #include <asm/page.h>
> >
> > +#include <kunit/test.h>
> > +
> >  /*
> >   * Note: test functions are marked noinline so that their names appear in
> >   * reports.
> >   */
> >
> > -static noinline void __init kmalloc_oob_right(void)
> > +static noinline void kmalloc_oob_right(void)
> >  {
> >         char *ptr;
> >         size_t size = 123;
> >
> > -       pr_info("out-of-bounds to right\n");
> >         ptr = kmalloc(size, GFP_KERNEL);
> >         if (!ptr) {
> >                 pr_err("Allocation failed\n");
> > @@ -44,12 +45,11 @@ static noinline void __init kmalloc_oob_right(void)
> >         kfree(ptr);
> >  }
> >
> > -static noinline void __init kmalloc_oob_left(void)
> > +static noinline void kmalloc_oob_left(void)
> >  {
> >         char *ptr;
> >         size_t size = 15;
> >
> > -       pr_info("out-of-bounds to left\n");
> >         ptr = kmalloc(size, GFP_KERNEL);
> >         if (!ptr) {
> >                 pr_err("Allocation failed\n");
> > @@ -60,12 +60,11 @@ static noinline void __init kmalloc_oob_left(void)
> >         kfree(ptr);
> >  }
> >
> > -static noinline void __init kmalloc_node_oob_right(void)
> > +static noinline void kmalloc_node_oob_right(void)
> >  {
> >         char *ptr;
> >         size_t size = 4096;
> >
> > -       pr_info("kmalloc_node(): out-of-bounds to right\n");
> >         ptr = kmalloc_node(size, GFP_KERNEL, 0);
> >         if (!ptr) {
> >                 pr_err("Allocation failed\n");
> > @@ -77,7 +76,7 @@ static noinline void __init kmalloc_node_oob_right(void)
> >  }
> >
> >  #ifdef CONFIG_SLUB
> > -static noinline void __init kmalloc_pagealloc_oob_right(void)
> > +static noinline void kmalloc_pagealloc_oob_right(void)
> >  {
> >         char *ptr;
> >         size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
> > @@ -85,7 +84,6 @@ static noinline void __init kmalloc_pagealloc_oob_right(void)
> >         /* Allocate a chunk that does not fit into a SLUB cache to trigger
> >          * the page allocator fallback.
> >          */
> > -       pr_info("kmalloc pagealloc allocation: out-of-bounds to right\n");
> >         ptr = kmalloc(size, GFP_KERNEL);
> >         if (!ptr) {
> >                 pr_err("Allocation failed\n");
> > @@ -96,12 +94,11 @@ static noinline void __init kmalloc_pagealloc_oob_right(void)
> >         kfree(ptr);
> >  }
> >
> > -static noinline void __init kmalloc_pagealloc_uaf(void)
> > +static noinline void kmalloc_pagealloc_uaf(void)
> >  {
> >         char *ptr;
> >         size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
> >
> > -       pr_info("kmalloc pagealloc allocation: use-after-free\n");
> >         ptr = kmalloc(size, GFP_KERNEL);
> >         if (!ptr) {
> >                 pr_err("Allocation failed\n");
> > @@ -112,12 +109,11 @@ static noinline void __init kmalloc_pagealloc_uaf(void)
> >         ptr[0] = 0;
> >  }
> >
> > -static noinline void __init kmalloc_pagealloc_invalid_free(void)
> > +static noinline void kmalloc_pagealloc_invalid_free(void)
> >  {
> >         char *ptr;
> >         size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
> >
> > -       pr_info("kmalloc pagealloc allocation: invalid-free\n");
> >         ptr = kmalloc(size, GFP_KERNEL);
> >         if (!ptr) {
> >                 pr_err("Allocation failed\n");
> > @@ -128,14 +124,13 @@ static noinline void __init kmalloc_pagealloc_invalid_free(void)
> >  }
> >  #endif
> >
> > -static noinline void __init kmalloc_large_oob_right(void)
> > +static noinline void kmalloc_large_oob_right(void)
> >  {
> >         char *ptr;
> >         size_t size = KMALLOC_MAX_CACHE_SIZE - 256;
> >         /* Allocate a chunk that is large enough, but still fits into a slab
> >          * and does not trigger the page allocator fallback in SLUB.
> >          */
> > -       pr_info("kmalloc large allocation: out-of-bounds to right\n");
> >         ptr = kmalloc(size, GFP_KERNEL);
> >         if (!ptr) {
> >                 pr_err("Allocation failed\n");
> > @@ -146,13 +141,12 @@ static noinline void __init kmalloc_large_oob_right(void)
> >         kfree(ptr);
> >  }
> >
> > -static noinline void __init kmalloc_oob_krealloc_more(void)
> > +static noinline void kmalloc_oob_krealloc_more(void)
> >  {
> >         char *ptr1, *ptr2;
> >         size_t size1 = 17;
> >         size_t size2 = 19;
> >
> > -       pr_info("out-of-bounds after krealloc more\n");
> >         ptr1 = kmalloc(size1, GFP_KERNEL);
> >         ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
> >         if (!ptr1 || !ptr2) {
> > @@ -166,13 +160,12 @@ static noinline void __init kmalloc_oob_krealloc_more(void)
> >         kfree(ptr2);
> >  }
> >
> > -static noinline void __init kmalloc_oob_krealloc_less(void)
> > +static noinline void kmalloc_oob_krealloc_less(void)
> >  {
> >         char *ptr1, *ptr2;
> >         size_t size1 = 17;
> >         size_t size2 = 15;
> >
> > -       pr_info("out-of-bounds after krealloc less\n");
> >         ptr1 = kmalloc(size1, GFP_KERNEL);
> >         ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
> >         if (!ptr1 || !ptr2) {
> > @@ -184,13 +177,12 @@ static noinline void __init kmalloc_oob_krealloc_less(void)
> >         kfree(ptr2);
> >  }
> >
> > -static noinline void __init kmalloc_oob_16(void)
> > +static noinline void kmalloc_oob_16(void)
> >  {
> >         struct {
> >                 u64 words[2];
> >         } *ptr1, *ptr2;
> >
> > -       pr_info("kmalloc out-of-bounds for 16-bytes access\n");
> >         ptr1 = kmalloc(sizeof(*ptr1) - 3, GFP_KERNEL);
> >         ptr2 = kmalloc(sizeof(*ptr2), GFP_KERNEL);
> >         if (!ptr1 || !ptr2) {
> > @@ -204,12 +196,11 @@ static noinline void __init kmalloc_oob_16(void)
> >         kfree(ptr2);
> >  }
> >
> > -static noinline void __init kmalloc_oob_memset_2(void)
> > +static noinline void kmalloc_oob_memset_2(void)
> >  {
> >         char *ptr;
> >         size_t size = 8;
> >
> > -       pr_info("out-of-bounds in memset2\n");
> >         ptr = kmalloc(size, GFP_KERNEL);
> >         if (!ptr) {
> >                 pr_err("Allocation failed\n");
> > @@ -220,12 +211,11 @@ static noinline void __init kmalloc_oob_memset_2(void)
> >         kfree(ptr);
> >  }
> >
> > -static noinline void __init kmalloc_oob_memset_4(void)
> > +static noinline void kmalloc_oob_memset_4(void)
> >  {
> >         char *ptr;
> >         size_t size = 8;
> >
> > -       pr_info("out-of-bounds in memset4\n");
> >         ptr = kmalloc(size, GFP_KERNEL);
> >         if (!ptr) {
> >                 pr_err("Allocation failed\n");
> > @@ -237,12 +227,11 @@ static noinline void __init kmalloc_oob_memset_4(void)
> >  }
> >
> >
> > -static noinline void __init kmalloc_oob_memset_8(void)
> > +static noinline void kmalloc_oob_memset_8(void)
> >  {
> >         char *ptr;
> >         size_t size = 8;
> >
> > -       pr_info("out-of-bounds in memset8\n");
> >         ptr = kmalloc(size, GFP_KERNEL);
> >         if (!ptr) {
> >                 pr_err("Allocation failed\n");
> > @@ -253,12 +242,11 @@ static noinline void __init kmalloc_oob_memset_8(void)
> >         kfree(ptr);
> >  }
> >
> > -static noinline void __init kmalloc_oob_memset_16(void)
> > +static noinline void kmalloc_oob_memset_16(void)
> >  {
> >         char *ptr;
> >         size_t size = 16;
> >
> > -       pr_info("out-of-bounds in memset16\n");
> >         ptr = kmalloc(size, GFP_KERNEL);
> >         if (!ptr) {
> >                 pr_err("Allocation failed\n");
> > @@ -269,12 +257,11 @@ static noinline void __init kmalloc_oob_memset_16(void)
> >         kfree(ptr);
> >  }
> >
> > -static noinline void __init kmalloc_oob_in_memset(void)
> > +static noinline void kmalloc_oob_in_memset(void)
> >  {
> >         char *ptr;
> >         size_t size = 666;
> >
> > -       pr_info("out-of-bounds in memset\n");
> >         ptr = kmalloc(size, GFP_KERNEL);
> >         if (!ptr) {
> >                 pr_err("Allocation failed\n");
> > @@ -285,12 +272,11 @@ static noinline void __init kmalloc_oob_in_memset(void)
> >         kfree(ptr);
> >  }
> >
> > -static noinline void __init kmalloc_uaf(void)
> > +static noinline void kmalloc_uaf(void)
> >  {
> >         char *ptr;
> >         size_t size = 10;
> >
> > -       pr_info("use-after-free\n");
> >         ptr = kmalloc(size, GFP_KERNEL);
> >         if (!ptr) {
> >                 pr_err("Allocation failed\n");
> > @@ -301,12 +287,11 @@ static noinline void __init kmalloc_uaf(void)
> >         *(ptr + 8) = 'x';
> >  }
> >
> > -static noinline void __init kmalloc_uaf_memset(void)
> > +static noinline void kmalloc_uaf_memset(void)
> >  {
> >         char *ptr;
> >         size_t size = 33;
> >
> > -       pr_info("use-after-free in memset\n");
> >         ptr = kmalloc(size, GFP_KERNEL);
> >         if (!ptr) {
> >                 pr_err("Allocation failed\n");
> > @@ -317,12 +302,11 @@ static noinline void __init kmalloc_uaf_memset(void)
> >         memset(ptr, 0, size);
> >  }
> >
> > -static noinline void __init kmalloc_uaf2(void)
> > +static noinline void kmalloc_uaf2(void)
> >  {
> >         char *ptr1, *ptr2;
> >         size_t size = 43;
> >
> > -       pr_info("use-after-free after another kmalloc\n");
> >         ptr1 = kmalloc(size, GFP_KERNEL);
> >         if (!ptr1) {
> >                 pr_err("Allocation failed\n");
> > @@ -342,14 +326,13 @@ static noinline void __init kmalloc_uaf2(void)
> >         kfree(ptr2);
> >  }
> >
> > -static noinline void __init kfree_via_page(void)
> > +static noinline void kfree_via_page(void)
> >  {
> >         char *ptr;
> >         size_t size = 8;
> >         struct page *page;
> >         unsigned long offset;
> >
> > -       pr_info("invalid-free false positive (via page)\n");
> >         ptr = kmalloc(size, GFP_KERNEL);
> >         if (!ptr) {
> >                 pr_err("Allocation failed\n");
> > @@ -361,13 +344,12 @@ static noinline void __init kfree_via_page(void)
> >         kfree(page_address(page) + offset);
> >  }
> >
> > -static noinline void __init kfree_via_phys(void)
> > +static noinline void kfree_via_phys(void)
> >  {
> >         char *ptr;
> >         size_t size = 8;
> >         phys_addr_t phys;
> >
> > -       pr_info("invalid-free false positive (via phys)\n");
> >         ptr = kmalloc(size, GFP_KERNEL);
> >         if (!ptr) {
> >                 pr_err("Allocation failed\n");
> > @@ -378,7 +360,7 @@ static noinline void __init kfree_via_phys(void)
> >         kfree(phys_to_virt(phys));
> >  }
> >
> > -static noinline void __init kmem_cache_oob(void)
> > +static noinline void kmem_cache_oob(void)
> >  {
> >         char *p;
> >         size_t size = 200;
> > @@ -389,7 +371,6 @@ static noinline void __init kmem_cache_oob(void)
> >                 pr_err("Cache allocation failed\n");
> >                 return;
> >         }
> > -       pr_info("out-of-bounds in kmem_cache_alloc\n");
> >         p = kmem_cache_alloc(cache, GFP_KERNEL);
> >         if (!p) {
> >                 pr_err("Allocation failed\n");
> > @@ -402,7 +383,7 @@ static noinline void __init kmem_cache_oob(void)
> >         kmem_cache_destroy(cache);
> >  }
> >
> > -static noinline void __init memcg_accounted_kmem_cache(void)
> > +static noinline void memcg_accounted_kmem_cache(void)
> >  {
> >         int i;
> >         char *p;
> > @@ -415,7 +396,6 @@ static noinline void __init memcg_accounted_kmem_cache(void)
> >                 return;
> >         }
> >
> > -       pr_info("allocate memcg accounted object\n");
> >         /*
> >          * Several allocations with a delay to allow for lazy per memcg kmem
> >          * cache creation.
> > @@ -435,31 +415,19 @@ static noinline void __init memcg_accounted_kmem_cache(void)
> >
> >  static char global_array[10];
> >
> > -static noinline void __init kasan_global_oob(void)
> > +static noinline void kasan_global_oob(void)
> >  {
> >         volatile int i = 3;
> >         char *p = &global_array[ARRAY_SIZE(global_array) + i];
> >
> > -       pr_info("out-of-bounds global variable\n");
> > -       *(volatile char *)p;
> > -}
> > -
> > -static noinline void __init kasan_stack_oob(void)
>
> Let's keep it but also make dependent on CONFIG_KASAN_STACK
>
> > -{
> > -       char stack_array[10];
> > -       volatile int i = 0;
> > -       char *p = &stack_array[ARRAY_SIZE(stack_array) + i];
> > -
> > -       pr_info("out-of-bounds on stack\n");
> >         *(volatile char *)p;
> >  }
> >
> > -static noinline void __init ksize_unpoisons_memory(void)
> > +static noinline void ksize_unpoisons_memory(void)
> >  {
> >         char *ptr;
> >         size_t size = 123, real_size;
> >
> > -       pr_info("ksize() unpoisons the whole allocated chunk\n");
> >         ptr = kmalloc(size, GFP_KERNEL);
> >         if (!ptr) {
> >                 pr_err("Allocation failed\n");
> > @@ -473,72 +441,36 @@ static noinline void __init ksize_unpoisons_memory(void)
> >         kfree(ptr);
> >  }
> >
> > -static noinline void __init copy_user_test(void)
> > +#if (CONFIG_KASAN_STACK == 1)
>
> The more common syntax for this is:
>
> #ifdef CONFIG_KASAN_STACK
>
> but it would even better to do:
>
> if (IS_ENABLED(CONFIG_KASAN_STACK))
>
> and return early. This way we at least test compilation (e.g.
> CONFIG_KASAN_STACK is not supported on your arch, you change tests and
> build break them because they were not even compiled).
>
>
Thank you!

> > +static noinline void kasan_stack_oob(void)
> >  {
> > -       char *kmem;
> > -       char __user *usermem;
> > -       size_t size = 10;
> > -       int unused;
> > -
> > -       kmem = kmalloc(size, GFP_KERNEL);
> > -       if (!kmem)
> > -               return;
> > -
> > -       usermem = (char __user *)vm_mmap(NULL, 0, PAGE_SIZE,
> > -                           PROT_READ | PROT_WRITE | PROT_EXEC,
> > -                           MAP_ANONYMOUS | MAP_PRIVATE, 0);
> > -       if (IS_ERR(usermem)) {
> > -               pr_err("Failed to allocate user memory\n");
> > -               kfree(kmem);
> > -               return;
> > -       }
> > -
> > -       pr_info("out-of-bounds in copy_from_user()\n");
> > -       unused = copy_from_user(kmem, usermem, size + 1);
>
> Why is all of this removed?
> Most of these tests are hard earned and test some special corner cases.
>
I just moved it inside IS_MODULE(CONFIG_TEST_KASAN) instead because I
don't think there is a way to rewrite this without it being a module.

> > -
> > -       pr_info("out-of-bounds in copy_to_user()\n");
> > -       unused = copy_to_user(usermem, kmem, size + 1);
> > -
> > -       pr_info("out-of-bounds in __copy_from_user()\n");
> > -       unused = __copy_from_user(kmem, usermem, size + 1);
> > -
> > -       pr_info("out-of-bounds in __copy_to_user()\n");
> > -       unused = __copy_to_user(usermem, kmem, size + 1);
> > -
> > -       pr_info("out-of-bounds in __copy_from_user_inatomic()\n");
> > -       unused = __copy_from_user_inatomic(kmem, usermem, size + 1);
> > -
> > -       pr_info("out-of-bounds in __copy_to_user_inatomic()\n");
> > -       unused = __copy_to_user_inatomic(usermem, kmem, size + 1);
> > -
> > -       pr_info("out-of-bounds in strncpy_from_user()\n");
> > -       unused = strncpy_from_user(kmem, usermem, size + 1);
> > +       char stack_array[10];
> > +       volatile int i = 0;
> > +       char *p = &stack_array[ARRAY_SIZE(stack_array) + i];
> >
> > -       vm_munmap((unsigned long)usermem, PAGE_SIZE);
> > -       kfree(kmem);
> > +       *(volatile char *)p;
> >  }
> >
> > -static noinline void __init kasan_alloca_oob_left(void)
> > +static noinline void kasan_alloca_oob_left(void)
> >  {
> >         volatile int i = 10;
> >         char alloca_array[i];
> >         char *p = alloca_array - 1;
> >
> > -       pr_info("out-of-bounds to left on alloca\n");
> >         *(volatile char *)p;
> >  }
> >
> > -static noinline void __init kasan_alloca_oob_right(void)
> > +static noinline void kasan_alloca_oob_right(void)
> >  {
> >         volatile int i = 10;
> >         char alloca_array[i];
> >         char *p = alloca_array + i;
> >
> > -       pr_info("out-of-bounds to right on alloca\n");
> >         *(volatile char *)p;
> >  }
> > +#endif /* CONFIG_KASAN_STACK */
> >
> > -static noinline void __init kmem_cache_double_free(void)
> > +static noinline void kmem_cache_double_free(void)
> >  {
> >         char *p;
> >         size_t size = 200;
> > @@ -549,7 +481,6 @@ static noinline void __init kmem_cache_double_free(void)
> >                 pr_err("Cache allocation failed\n");
> >                 return;
> >         }
> > -       pr_info("double-free on heap object\n");
> >         p = kmem_cache_alloc(cache, GFP_KERNEL);
> >         if (!p) {
> >                 pr_err("Allocation failed\n");
> > @@ -562,7 +493,7 @@ static noinline void __init kmem_cache_double_free(void)
> >         kmem_cache_destroy(cache);
> >  }
> >
> > -static noinline void __init kmem_cache_invalid_free(void)
> > +static noinline void kmem_cache_invalid_free(void)
> >  {
> >         char *p;
> >         size_t size = 200;
> > @@ -574,7 +505,6 @@ static noinline void __init kmem_cache_invalid_free(void)
> >                 pr_err("Cache allocation failed\n");
> >                 return;
> >         }
> > -       pr_info("invalid-free of heap object\n");
> >         p = kmem_cache_alloc(cache, GFP_KERNEL);
> >         if (!p) {
> >                 pr_err("Allocation failed\n");
> > @@ -594,12 +524,11 @@ static noinline void __init kmem_cache_invalid_free(void)
> >         kmem_cache_destroy(cache);
> >  }
> >
> > -static noinline void __init kasan_memchr(void)
> > +static noinline void kasan_memchr(void)
> >  {
> >         char *ptr;
> >         size_t size = 24;
> >
> > -       pr_info("out-of-bounds in memchr\n");
> >         ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO);
> >         if (!ptr)
> >                 return;
> > @@ -608,13 +537,12 @@ static noinline void __init kasan_memchr(void)
> >         kfree(ptr);
> >  }
> >
> > -static noinline void __init kasan_memcmp(void)
> > +static noinline void kasan_memcmp(void)
> >  {
> >         char *ptr;
> >         size_t size = 24;
> >         int arr[9];
> >
> > -       pr_info("out-of-bounds in memcmp\n");
> >         ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO);
> >         if (!ptr)
> >                 return;
> > @@ -624,12 +552,11 @@ static noinline void __init kasan_memcmp(void)
> >         kfree(ptr);
> >  }
> >
> > -static noinline void __init kasan_strings(void)
> > +static noinline void kasan_strings(void)
> >  {
> >         char *ptr;
> >         size_t size = 24;
> >
> > -       pr_info("use-after-free in strchr\n");
> >         ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO);
> >         if (!ptr)
> >                 return;
> > @@ -645,23 +572,18 @@ static noinline void __init kasan_strings(void)
> >         ptr += 16;
> >         strchr(ptr, '1');
> >
> > -       pr_info("use-after-free in strrchr\n");
> >         strrchr(ptr, '1');
> >
> > -       pr_info("use-after-free in strcmp\n");
> >         strcmp(ptr, "2");
>
> Such tests now need to be split into multiple tests, one error per
> test. Otherwise they don't test what they are supposed to test (each
> of these produces an error).
> Well, I mean, currently they don't test anything at all, but with
> kunit we actually can test this, so it would be good to actually test
> what this test was supposed to test :)
> This applies to other tests as well.
>
I didn't realize. I'll split up those tests for v2.

>
> > -       pr_info("use-after-free in strncmp\n");
> >         strncmp(ptr, "2", 1);
> >
> > -       pr_info("use-after-free in strlen\n");
> >         strlen(ptr);
> >
> > -       pr_info("use-after-free in strnlen\n");
> >         strnlen(ptr, 1);
> >  }
> >
> > -static noinline void __init kasan_bitops(void)
> > +static noinline void kasan_bitops(void)
> >  {
> >         /*
> >          * Allocate 1 more byte, which causes kzalloc to round up to 16-bytes;
> > @@ -676,70 +598,52 @@ static noinline void __init kasan_bitops(void)
> >          * below accesses are still out-of-bounds, since bitops are defined to
> >          * operate on the whole long the bit is in.
> >          */
> > -       pr_info("out-of-bounds in set_bit\n");
> >         set_bit(BITS_PER_LONG, bits);
> >
> > -       pr_info("out-of-bounds in __set_bit\n");
> >         __set_bit(BITS_PER_LONG, bits);
> >
> > -       pr_info("out-of-bounds in clear_bit\n");
> >         clear_bit(BITS_PER_LONG, bits);
> >
> > -       pr_info("out-of-bounds in __clear_bit\n");
> >         __clear_bit(BITS_PER_LONG, bits);
> >
> > -       pr_info("out-of-bounds in clear_bit_unlock\n");
> >         clear_bit_unlock(BITS_PER_LONG, bits);
> >
> > -       pr_info("out-of-bounds in __clear_bit_unlock\n");
> >         __clear_bit_unlock(BITS_PER_LONG, bits);
> >
> > -       pr_info("out-of-bounds in change_bit\n");
> >         change_bit(BITS_PER_LONG, bits);
> >
> > -       pr_info("out-of-bounds in __change_bit\n");
> >         __change_bit(BITS_PER_LONG, bits);
> >
> >         /*
> >          * Below calls try to access bit beyond allocated memory.
> >          */
> > -       pr_info("out-of-bounds in test_and_set_bit\n");
> >         test_and_set_bit(BITS_PER_LONG + BITS_PER_BYTE, bits);
> >
> > -       pr_info("out-of-bounds in __test_and_set_bit\n");
> >         __test_and_set_bit(BITS_PER_LONG + BITS_PER_BYTE, bits);
> >
> > -       pr_info("out-of-bounds in test_and_set_bit_lock\n");
> >         test_and_set_bit_lock(BITS_PER_LONG + BITS_PER_BYTE, bits);
> >
> > -       pr_info("out-of-bounds in test_and_clear_bit\n");
> >         test_and_clear_bit(BITS_PER_LONG + BITS_PER_BYTE, bits);
> >
> > -       pr_info("out-of-bounds in __test_and_clear_bit\n");
> >         __test_and_clear_bit(BITS_PER_LONG + BITS_PER_BYTE, bits);
> >
> > -       pr_info("out-of-bounds in test_and_change_bit\n");
> >         test_and_change_bit(BITS_PER_LONG + BITS_PER_BYTE, bits);
> >
> > -       pr_info("out-of-bounds in __test_and_change_bit\n");
> >         __test_and_change_bit(BITS_PER_LONG + BITS_PER_BYTE, bits);
> >
> > -       pr_info("out-of-bounds in test_bit\n");
> >         (void)test_bit(BITS_PER_LONG + BITS_PER_BYTE, bits);
> >
> >  #if defined(clear_bit_unlock_is_negative_byte)
> > -       pr_info("out-of-bounds in clear_bit_unlock_is_negative_byte\n");
> >         clear_bit_unlock_is_negative_byte(BITS_PER_LONG + BITS_PER_BYTE, bits);
> >  #endif
> >         kfree(bits);
> >  }
> >
> > -static noinline void __init kmalloc_double_kzfree(void)
> > +static noinline void kmalloc_double_kzfree(void)
>
> Since it seems we will need v2, it will help if you move these
> mechanical diffs to a separate patch. I mean removal of __init and
> pr_info. These produce lots of changes and it's hard to separate out
> more meaningful changes from this mechanical noise.
>
Good point!

> >  {
> >         char *ptr;
> >         size_t size = 16;
> >
> > -       pr_info("double-free (kzfree)\n");
> >         ptr = kmalloc(size, GFP_KERNEL);
> >         if (!ptr) {
> >                 pr_err("Allocation failed\n");
> > @@ -750,29 +654,130 @@ static noinline void __init kmalloc_double_kzfree(void)
> >         kzfree(ptr);
> >  }
> >
> > -#ifdef CONFIG_KASAN_VMALLOC
> > -static noinline void __init vmalloc_oob(void)
> > +static void kunit_test_oob(struct kunit *test)
> > +{
> > +       KUNIT_EXPECT_KASAN_FAIL(test, kmalloc_oob_right());
>
> I think the 2 patches need to be reordered. This
> KUNIT_EXPECT_KASAN_FAIL is introduced only in the next patch. This
> will break build during bisections.
>
This makes sense. I will reorder them for v2

> > +       KUNIT_EXPECT_KASAN_FAIL(test, kmalloc_oob_left());
>
> I am wondering if it makes sense to have the "KASAN_FAIL" part be part
> of the test itself. It will make the test and assertion local to each
> other. I hope later we will add some negative tests as well (without
> kasan errors), then people will start copy-pasting these macros and
> it's possible I copy-paste macro that checks that the test does not
> produce kasan error for my test, which I actually want the macro that
> checks for report. Then if my test does not fail, it will be
> unnoticed. I may be good to have assertion local to the test itself.
> Thoughts?
>
Alan suggested this as well. Since I can't imagine another place where
these expectations will be used, I will move the definition of
KUNIT_EXPECT_KASAN_FAILURE into test_kasan.c.

> > +       KUNIT_EXPECT_KASAN_FAIL(test, kmalloc_node_oob_right());
> > +       KUNIT_EXPECT_KASAN_FAIL(test, kmalloc_large_oob_right());
> > +       KUNIT_EXPECT_KASAN_FAIL(test, kmalloc_oob_krealloc_more());
> > +       KUNIT_EXPECT_KASAN_FAIL(test, kmalloc_oob_krealloc_less());
> > +       KUNIT_EXPECT_KASAN_FAIL(test, kmalloc_oob_16());
> > +       KUNIT_EXPECT_KASAN_FAIL(test, kmalloc_oob_in_memset());
> > +       KUNIT_EXPECT_KASAN_FAIL(test, kmalloc_oob_memset_2());
> > +       KUNIT_EXPECT_KASAN_FAIL(test, kmalloc_oob_memset_4());
> > +       KUNIT_EXPECT_KASAN_FAIL(test, kmalloc_oob_memset_8());
> > +       KUNIT_EXPECT_KASAN_FAIL(test, kmalloc_oob_memset_16());
> > +       KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_oob());
> > +       KUNIT_EXPECT_KASAN_FAIL(test, kasan_global_oob());
> > +       KUNIT_EXPECT_KASAN_FAIL(test, ksize_unpoisons_memory());
> > +       KUNIT_EXPECT_KASAN_FAIL(test, kasan_memchr());
> > +       KUNIT_EXPECT_KASAN_FAIL(test, kasan_memcmp());
> > +       KUNIT_EXPECT_KASAN_FAIL(test, kasan_strings());
> > +       KUNIT_EXPECT_KASAN_FAIL(test, kasan_bitops());
> > +#ifdef CONFIG_SLUB
> > +       KUNIT_EXPECT_KASAN_FAIL(test, kmalloc_pagealloc_oob_right());
> > +#endif /* CONFIG_SLUB */
> > +
> > +#if (CONFIG_KASAN_STACK == 1)
> > +       KUNIT_EXPECT_KASAN_FAIL(test, kasan_stack_oob());
> > +       KUNIT_EXPECT_KASAN_FAIL(test, kasan_alloca_oob_right());
> > +       KUNIT_EXPECT_KASAN_FAIL(test, kasan_alloca_oob_left());
> > +#endif /*CONFIG_KASAN_STACK*/
> > +}
> > +
> > +static void kunit_test_uaf(struct kunit *test)
> > +{
> > +#ifdef CONFIG_SLUB
> > +       KUNIT_EXPECT_KASAN_FAIL(test, kmalloc_pagealloc_uaf());
> > +#endif
> > +       KUNIT_EXPECT_KASAN_FAIL(test, kmalloc_uaf());
> > +       KUNIT_EXPECT_KASAN_FAIL(test, kmalloc_uaf_memset());
> > +       KUNIT_EXPECT_KASAN_FAIL(test, kmalloc_uaf2());
> > +}
> > +
> > +static void kunit_test_invalid_free(struct kunit *test)
> >  {
> > -       void *area;
> > +#ifdef CONFIG_SLUB
> > +       KUNIT_EXPECT_KASAN_FAIL(test, kmalloc_pagealloc_invalid_free());
> > +#endif
> > +       KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_invalid_free());
> > +       KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_double_free());
> > +       KUNIT_EXPECT_KASAN_FAIL(test, kmalloc_double_kzfree());
> > +}
> >
> > -       pr_info("vmalloc out-of-bounds\n");
> > +static void kunit_test_false_positives(struct kunit *test)
> > +{
> > +       kfree_via_page();
> > +       kfree_via_phys();
> > +}
> >
> > -       /*
> > -        * We have to be careful not to hit the guard page.
> > -        * The MMU will catch that and crash us.
> > -        */
> > -       area = vmalloc(3000);
> > -       if (!area) {
> > -               pr_err("Allocation failed\n");
> > +static void kunit_test_memcg(struct kunit *test)
> > +{
> > +       memcg_accounted_kmem_cache();
> > +}
> > +
> > +static struct kunit_case kasan_kunit_test_cases[] = {
> > +       KUNIT_CASE(kunit_test_oob),
> > +       KUNIT_CASE(kunit_test_uaf),
> > +       KUNIT_CASE(kunit_test_invalid_free),
> > +       KUNIT_CASE(kunit_test_false_positives),
> > +       KUNIT_CASE(kunit_test_memcg),
> > +       {}
> > +};
> > +
> > +static struct kunit_suite kasan_kunit_test_suite = {
> > +       .name = "kasan_kunit_test",
> > +       .test_cases = kasan_kunit_test_cases,
> > +};
> > +
> > +kunit_test_suite(kasan_kunit_test_suite);
> > +
> > +#if IS_MODULE(CONFIG_TEST_KASAN)
> > +static noinline void __init copy_user_test(void)
> > +{
> > +       char *kmem;
> > +       char __user *usermem;
> > +       size_t size = 10;
> > +       int unused;
> > +
> > +       kmem = kmalloc(size, GFP_KERNEL);
> > +       if (!kmem)
> > +               return;
> > +
> > +       usermem = (char __user *)vm_mmap(NULL, 0, PAGE_SIZE,
> > +                           PROT_READ | PROT_WRITE | PROT_EXEC,
> > +                           MAP_ANONYMOUS | MAP_PRIVATE, 0);
> > +       if (IS_ERR(usermem)) {
> > +               pr_err("Failed to allocate user memory\n");
> > +               kfree(kmem);
> >                 return;
> >         }
> >
> > -       ((volatile char *)area)[3100];
> > -       vfree(area);
> > +       pr_info("out-of-bounds in copy_from_user()\n");
> > +       unused = copy_from_user(kmem, usermem, size + 1);
> > +
> > +       pr_info("out-of-bounds in copy_to_user()\n");
> > +       unused = copy_to_user(usermem, kmem, size + 1);
> > +
> > +       pr_info("out-of-bounds in __copy_from_user()\n");
> > +       unused = __copy_from_user(kmem, usermem, size + 1);
> > +
> > +       pr_info("out-of-bounds in __copy_to_user()\n");
> > +       unused = __copy_to_user(usermem, kmem, size + 1);
> > +
> > +       pr_info("out-of-bounds in __copy_from_user_inatomic()\n");
> > +       unused = __copy_from_user_inatomic(kmem, usermem, size + 1);
> > +
> > +       pr_info("out-of-bounds in __copy_to_user_inatomic()\n");
> > +       unused = __copy_to_user_inatomic(usermem, kmem, size + 1);
> > +
> > +       pr_info("out-of-bounds in strncpy_from_user()\n");
> > +       unused = strncpy_from_user(kmem, usermem, size + 1);
> > +
> > +       vm_munmap((unsigned long)usermem, PAGE_SIZE);
> > +       kfree(kmem);
> >  }
> > -#else
> > -static void __init vmalloc_oob(void) {}
> > -#endif
> >
> >  static int __init kmalloc_tests_init(void)
> >  {
> > @@ -782,44 +787,7 @@ static int __init kmalloc_tests_init(void)
> >          */
> >         bool multishot = kasan_save_enable_multi_shot();
> >
> > -       kmalloc_oob_right();
> > -       kmalloc_oob_left();
> > -       kmalloc_node_oob_right();
> > -#ifdef CONFIG_SLUB
> > -       kmalloc_pagealloc_oob_right();
> > -       kmalloc_pagealloc_uaf();
> > -       kmalloc_pagealloc_invalid_free();
> > -#endif
> > -       kmalloc_large_oob_right();
> > -       kmalloc_oob_krealloc_more();
> > -       kmalloc_oob_krealloc_less();
> > -       kmalloc_oob_16();
> > -       kmalloc_oob_in_memset();
> > -       kmalloc_oob_memset_2();
> > -       kmalloc_oob_memset_4();
> > -       kmalloc_oob_memset_8();
> > -       kmalloc_oob_memset_16();
> > -       kmalloc_uaf();
> > -       kmalloc_uaf_memset();
> > -       kmalloc_uaf2();
> > -       kfree_via_page();
> > -       kfree_via_phys();
> > -       kmem_cache_oob();
> > -       memcg_accounted_kmem_cache();
> > -       kasan_stack_oob();
> > -       kasan_global_oob();
> > -       kasan_alloca_oob_left();
> > -       kasan_alloca_oob_right();
> > -       ksize_unpoisons_memory();
> >         copy_user_test();
> > -       kmem_cache_double_free();
> > -       kmem_cache_invalid_free();
> > -       kasan_memchr();
> > -       kasan_memcmp();
> > -       kasan_strings();
> > -       kasan_bitops();
> > -       kmalloc_double_kzfree();
> > -       vmalloc_oob();
> >
> >         kasan_restore_multi_shot(multishot);
> >
> > @@ -827,4 +795,4 @@ static int __init kmalloc_tests_init(void)
> >  }
> >
> >  module_init(kmalloc_tests_init);
> > -MODULE_LICENSE("GPL");
> > +#endif /* IS_MODULE(CONFIG_TEST_KASAN) */
> > --
> > 2.25.0.265.gbab2e86ba0-goog
> >



-- 
Thanks!
Patricia Alfonso