| Message ID | 20200325161249.55095-14-glider@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add KernelMemorySanitizer infrastructure | expand |
On Wed, Mar 25, 2020 at 5:13 PM <glider@google.com> wrote: > > The initial commit adds several tests that trigger KMSAN warnings in > simple cases. > To use, build the kernel with CONFIG_TEST_KMSAN and do > `insmod test_kmsan.ko` > > Signed-off-by: Alexander Potapenko <glider@google.com> > To: Alexander Potapenko <glider@google.com> > Cc: Vegard Nossum <vegard.nossum@oracle.com> > Cc: Dmitry Vyukov <dvyukov@google.com> > Cc: Marco Elver <elver@google.com> > Cc: Andrey Konovalov <andreyknvl@google.com> > Cc: linux-mm@kvack.org > --- > v2: > - added printk_test() > v4: > - test_kmsan: don't report -Wuninitialized warnings in the test > - test_kmsan.c: addressed comments by Andrey Konovalov > > Change-Id: I287e86ae83a82b770f2baa46e5bbdce1dfa65195 > --- > lib/Makefile | 2 + > lib/test_kmsan.c | 229 +++++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 231 insertions(+) > create mode 100644 lib/test_kmsan.c > > diff --git a/lib/Makefile b/lib/Makefile > index ab68a86743607..d8058c5c05826 100644 > --- a/lib/Makefile > +++ b/lib/Makefile > @@ -68,6 +68,8 @@ CFLAGS_test_kasan.o += $(call cc-disable-warning, vla) > obj-$(CONFIG_TEST_UBSAN) += test_ubsan.o > CFLAGS_test_ubsan.o += $(call cc-disable-warning, vla) > UBSAN_SANITIZE_test_ubsan.o := y > +obj-$(CONFIG_TEST_KMSAN) += test_kmsan.o > +CFLAGS_test_kmsan.o += $(call cc-disable-warning, uninitialized) > obj-$(CONFIG_TEST_KSTRTOX) += test-kstrtox.o > obj-$(CONFIG_TEST_LIST_SORT) += test_list_sort.o > obj-$(CONFIG_TEST_MIN_HEAP) += test_min_heap.o > diff --git a/lib/test_kmsan.c b/lib/test_kmsan.c > new file mode 100644 > index 0000000000000..f1780ed0cd315 > --- /dev/null > +++ b/lib/test_kmsan.c > @@ -0,0 +1,229 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Module for testing KMSAN. > + * > + * Copyright (C) 2017-2019 Google LLC > + * Author: Alexander Potapenko <glider@google.com> > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + * > + */ > + > +/* > + * Tests below use noinline and volatile to work around compiler optimizations > + * that may mask KMSAN bugs. > + */ > +#define pr_fmt(fmt) "kmsan test: %s : " fmt, __func__ > + > +#include <linux/mm.h> > +#include <linux/module.h> > +#include <linux/printk.h> > +#include <linux/slab.h> > +#include <linux/kmsan-checks.h> > + > +#define CHECK(x) \ > + do { \ > + if (x) \ > + pr_info(#x " is true\n"); \ > + else \ > + pr_info(#x " is false\n"); \ > + } while (0) > + > +int signed_sum3(int a, int b, int c) static here and below. Also makes sense to move this function closer to uninit_multiple_args_test(). > +{ > + return a + b + c; > +} > + > +noinline void uninit_kmalloc_test(void) > +{ > + int *ptr; > + > + pr_info("-----------------------------\n"); > + pr_info("uninitialized kmalloc test (UMR report)\n"); > + ptr = kmalloc(sizeof(int), GFP_KERNEL); > + pr_info("kmalloc returned %p\n", ptr); > + CHECK(*ptr); kfree(ptr) here and below. In KASAN tests we also check that kmalloc() succeeds, but I don't have a strong opinion on whether we should do that. > +} > +noinline void init_kmalloc_test(void) > +{ > + int *ptr; > + > + pr_info("-----------------------------\n"); > + pr_info("initialized kmalloc test (no reports)\n"); > + ptr = kmalloc(sizeof(int), GFP_KERNEL); > + memset(ptr, 0, sizeof(int)); > + pr_info("kmalloc returned %p\n", ptr); > + CHECK(*ptr); > +} > + > +noinline void init_kzalloc_test(void) > +{ > + int *ptr; > + > + pr_info("-----------------------------\n"); > + pr_info("initialized kzalloc test (no reports)\n"); > + ptr = kzalloc(sizeof(int), GFP_KERNEL); > + pr_info("kzalloc returned %p\n", ptr); > + CHECK(*ptr); > +} > + > +noinline void uninit_multiple_args_test(void) > +{ > + volatile int a; > + volatile char b = 3, c; > + > + pr_info("-----------------------------\n"); > + pr_info("uninitialized local passed to fn (UMR report)\n"); > + CHECK(signed_sum3(a, b, c)); > +} > + > +noinline void uninit_stack_var_test(void) > +{ > + int cond; > + > + pr_info("-----------------------------\n"); > + pr_info("uninitialized stack variable (UMR report)\n"); > + CHECK(cond); > +} > + > +noinline void init_stack_var_test(void) > +{ > + volatile int cond = 1; > + > + pr_info("-----------------------------\n"); > + pr_info("initialized stack variable (no reports)\n"); > + CHECK(cond); > +} > + > +noinline void two_param_fn_2(int arg1, int arg2) > +{ > + CHECK(arg1); > + CHECK(arg2); > +} > + > +noinline void one_param_fn(int arg) > +{ > + two_param_fn_2(arg, arg); > + CHECK(arg); > +} > + > +noinline void two_param_fn(int arg1, int arg2) > +{ > + int init = 0; > + > + one_param_fn(init); > + CHECK(arg1); > + CHECK(arg2); > +} > + > +noinline void params_test(void) > +{ > + volatile int uninit, init = 1; > + > + pr_info("-----------------------------\n"); > + pr_info("uninit passed through a function parameter (UMR report)\n"); > + two_param_fn(uninit, init); > +} > + > +noinline void do_uninit_local_array(char *array, int start, int stop) > +{ > + int i; > + volatile char uninit; > + > + for (i = start; i < stop; i++) > + array[i] = uninit; > +} > + > +noinline void uninit_kmsan_check_memory_test(void) > +{ > + volatile char local_array[8]; > + > + pr_info("-----------------------------\n"); > + pr_info("kmsan_check_memory() called on uninit local (UMR report)\n"); > + do_uninit_local_array((char *)local_array, 5, 7); > + > + kmsan_check_memory((char *)local_array, 8); > +} > + > +noinline void init_kmsan_vmap_vunmap_test(void) > +{ > + const int npages = 2; > + struct page *pages[npages]; > + void *vbuf; > + int i; > + > + pr_info("-----------------------------\n"); > + pr_info("pages initialized via vmap (no reports)\n"); > + > + for (i = 0; i < npages; i++) > + pages[i] = alloc_page(GFP_KERNEL); > + vbuf = vmap(pages, npages, VM_MAP, PAGE_KERNEL); > + memset(vbuf, 0xfe, npages * PAGE_SIZE); > + for (i = 0; i < npages; i++) > + kmsan_check_memory(page_address(pages[i]), PAGE_SIZE); > + > + if (vbuf) > + vunmap(vbuf); > + for (i = 0; i < npages; i++) > + if (pages[i]) > + __free_page(pages[i]); > +} > + > +noinline void init_vmalloc_test(void) > +{ > + char *buf; > + int npages = 8, i; > + > + pr_info("-----------------------------\n"); > + pr_info("pages initialized via vmap (no reports)\n"); > + buf = vmalloc(PAGE_SIZE * npages); > + buf[0] = 1; > + memset(buf, 0xfe, PAGE_SIZE * npages); > + CHECK(buf[0]); > + for (i = 0; i < npages; i++) > + kmsan_check_memory(&buf[PAGE_SIZE * i], PAGE_SIZE); > + vfree(buf); > +} > + > +noinline void uaf_test(void) > +{ > + volatile int *var; > + > + pr_info("-----------------------------\n"); > + pr_info("use-after-free in kmalloc-ed buffer (UMR report)\n"); > + var = kmalloc(80, GFP_KERNEL); > + var[3] = 0xfeedface; > + kfree((int *)var); > + CHECK(var[3]); > +} > + > +noinline void printk_test(void) > +{ > + volatile int uninit; > + > + pr_info("-----------------------------\n"); > + pr_info("uninit local passed to pr_info() (UMR report)\n"); > + pr_info("%px contains %d\n", &uninit, uninit); > +} > + > +static noinline int __init kmsan_tests_init(void) > +{ > + uninit_kmalloc_test(); > + init_kmalloc_test(); > + init_kzalloc_test(); > + uninit_multiple_args_test(); > + uninit_stack_var_test(); > + init_stack_var_test(); > + params_test(); > + uninit_kmsan_check_memory_test(); > + init_kmsan_vmap_vunmap_test(); > + init_vmalloc_test(); > + uaf_test(); > + printk_test(); > + return -EAGAIN; > +} > + > +module_init(kmsan_tests_init); > +MODULE_LICENSE("GPL"); > -- > 2.25.1.696.g5e7596f4ac-goog >
diff --git a/lib/Makefile b/lib/Makefile index ab68a86743607..d8058c5c05826 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -68,6 +68,8 @@ CFLAGS_test_kasan.o += $(call cc-disable-warning, vla) obj-$(CONFIG_TEST_UBSAN) += test_ubsan.o CFLAGS_test_ubsan.o += $(call cc-disable-warning, vla) UBSAN_SANITIZE_test_ubsan.o := y +obj-$(CONFIG_TEST_KMSAN) += test_kmsan.o +CFLAGS_test_kmsan.o += $(call cc-disable-warning, uninitialized) obj-$(CONFIG_TEST_KSTRTOX) += test-kstrtox.o obj-$(CONFIG_TEST_LIST_SORT) += test_list_sort.o obj-$(CONFIG_TEST_MIN_HEAP) += test_min_heap.o diff --git a/lib/test_kmsan.c b/lib/test_kmsan.c new file mode 100644 index 0000000000000..f1780ed0cd315 --- /dev/null +++ b/lib/test_kmsan.c @@ -0,0 +1,229 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Module for testing KMSAN. + * + * Copyright (C) 2017-2019 Google LLC + * Author: Alexander Potapenko <glider@google.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +/* + * Tests below use noinline and volatile to work around compiler optimizations + * that may mask KMSAN bugs. + */ +#define pr_fmt(fmt) "kmsan test: %s : " fmt, __func__ + +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/printk.h> +#include <linux/slab.h> +#include <linux/kmsan-checks.h> + +#define CHECK(x) \ + do { \ + if (x) \ + pr_info(#x " is true\n"); \ + else \ + pr_info(#x " is false\n"); \ + } while (0) + +int signed_sum3(int a, int b, int c) +{ + return a + b + c; +} + +noinline void uninit_kmalloc_test(void) +{ + int *ptr; + + pr_info("-----------------------------\n"); + pr_info("uninitialized kmalloc test (UMR report)\n"); + ptr = kmalloc(sizeof(int), GFP_KERNEL); + pr_info("kmalloc returned %p\n", ptr); + CHECK(*ptr); +} +noinline void init_kmalloc_test(void) +{ + int *ptr; + + pr_info("-----------------------------\n"); + pr_info("initialized kmalloc test (no reports)\n"); + ptr = kmalloc(sizeof(int), GFP_KERNEL); + memset(ptr, 0, sizeof(int)); + pr_info("kmalloc returned %p\n", ptr); + CHECK(*ptr); +} + +noinline void init_kzalloc_test(void) +{ + int *ptr; + + pr_info("-----------------------------\n"); + pr_info("initialized kzalloc test (no reports)\n"); + ptr = kzalloc(sizeof(int), GFP_KERNEL); + pr_info("kzalloc returned %p\n", ptr); + CHECK(*ptr); +} + +noinline void uninit_multiple_args_test(void) +{ + volatile int a; + volatile char b = 3, c; + + pr_info("-----------------------------\n"); + pr_info("uninitialized local passed to fn (UMR report)\n"); + CHECK(signed_sum3(a, b, c)); +} + +noinline void uninit_stack_var_test(void) +{ + int cond; + + pr_info("-----------------------------\n"); + pr_info("uninitialized stack variable (UMR report)\n"); + CHECK(cond); +} + +noinline void init_stack_var_test(void) +{ + volatile int cond = 1; + + pr_info("-----------------------------\n"); + pr_info("initialized stack variable (no reports)\n"); + CHECK(cond); +} + +noinline void two_param_fn_2(int arg1, int arg2) +{ + CHECK(arg1); + CHECK(arg2); +} + +noinline void one_param_fn(int arg) +{ + two_param_fn_2(arg, arg); + CHECK(arg); +} + +noinline void two_param_fn(int arg1, int arg2) +{ + int init = 0; + + one_param_fn(init); + CHECK(arg1); + CHECK(arg2); +} + +noinline void params_test(void) +{ + volatile int uninit, init = 1; + + pr_info("-----------------------------\n"); + pr_info("uninit passed through a function parameter (UMR report)\n"); + two_param_fn(uninit, init); +} + +noinline void do_uninit_local_array(char *array, int start, int stop) +{ + int i; + volatile char uninit; + + for (i = start; i < stop; i++) + array[i] = uninit; +} + +noinline void uninit_kmsan_check_memory_test(void) +{ + volatile char local_array[8]; + + pr_info("-----------------------------\n"); + pr_info("kmsan_check_memory() called on uninit local (UMR report)\n"); + do_uninit_local_array((char *)local_array, 5, 7); + + kmsan_check_memory((char *)local_array, 8); +} + +noinline void init_kmsan_vmap_vunmap_test(void) +{ + const int npages = 2; + struct page *pages[npages]; + void *vbuf; + int i; + + pr_info("-----------------------------\n"); + pr_info("pages initialized via vmap (no reports)\n"); + + for (i = 0; i < npages; i++) + pages[i] = alloc_page(GFP_KERNEL); + vbuf = vmap(pages, npages, VM_MAP, PAGE_KERNEL); + memset(vbuf, 0xfe, npages * PAGE_SIZE); + for (i = 0; i < npages; i++) + kmsan_check_memory(page_address(pages[i]), PAGE_SIZE); + + if (vbuf) + vunmap(vbuf); + for (i = 0; i < npages; i++) + if (pages[i]) + __free_page(pages[i]); +} + +noinline void init_vmalloc_test(void) +{ + char *buf; + int npages = 8, i; + + pr_info("-----------------------------\n"); + pr_info("pages initialized via vmap (no reports)\n"); + buf = vmalloc(PAGE_SIZE * npages); + buf[0] = 1; + memset(buf, 0xfe, PAGE_SIZE * npages); + CHECK(buf[0]); + for (i = 0; i < npages; i++) + kmsan_check_memory(&buf[PAGE_SIZE * i], PAGE_SIZE); + vfree(buf); +} + +noinline void uaf_test(void) +{ + volatile int *var; + + pr_info("-----------------------------\n"); + pr_info("use-after-free in kmalloc-ed buffer (UMR report)\n"); + var = kmalloc(80, GFP_KERNEL); + var[3] = 0xfeedface; + kfree((int *)var); + CHECK(var[3]); +} + +noinline void printk_test(void) +{ + volatile int uninit; + + pr_info("-----------------------------\n"); + pr_info("uninit local passed to pr_info() (UMR report)\n"); + pr_info("%px contains %d\n", &uninit, uninit); +} + +static noinline int __init kmsan_tests_init(void) +{ + uninit_kmalloc_test(); + init_kmalloc_test(); + init_kzalloc_test(); + uninit_multiple_args_test(); + uninit_stack_var_test(); + init_stack_var_test(); + params_test(); + uninit_kmsan_check_memory_test(); + init_kmsan_vmap_vunmap_test(); + init_vmalloc_test(); + uaf_test(); + printk_test(); + return -EAGAIN; +} + +module_init(kmsan_tests_init); +MODULE_LICENSE("GPL");
The initial commit adds several tests that trigger KMSAN warnings in simple cases. To use, build the kernel with CONFIG_TEST_KMSAN and do `insmod test_kmsan.ko` Signed-off-by: Alexander Potapenko <glider@google.com> To: Alexander Potapenko <glider@google.com> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Marco Elver <elver@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: linux-mm@kvack.org --- v2: - added printk_test() v4: - test_kmsan: don't report -Wuninitialized warnings in the test - test_kmsan.c: addressed comments by Andrey Konovalov Change-Id: I287e86ae83a82b770f2baa46e5bbdce1dfa65195 --- lib/Makefile | 2 + lib/test_kmsan.c | 229 +++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 231 insertions(+) create mode 100644 lib/test_kmsan.c