Merge tag 'hardening-v6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees...
[platform/kernel/linux-starfive.git] / mm / kasan / kasan_test.c
index 7368464..74cd80c 100644 (file)
@@ -5,8 +5,12 @@
  * Author: Andrey Ryabinin <a.ryabinin@samsung.com>
  */
 
+#define pr_fmt(fmt) "kasan_test: " fmt
+
+#include <kunit/test.h>
 #include <linux/bitops.h>
 #include <linux/delay.h>
+#include <linux/io.h>
 #include <linux/kasan.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/printk.h>
 #include <linux/random.h>
+#include <linux/set_memory.h>
 #include <linux/slab.h>
 #include <linux/string.h>
+#include <linux/tracepoint.h>
 #include <linux/uaccess.h>
-#include <linux/io.h>
 #include <linux/vmalloc.h>
-#include <linux/set_memory.h>
+#include <trace/events/printk.h>
 
 #include <asm/page.h>
 
-#include <kunit/test.h>
-
 #include "kasan.h"
 
 #define OOB_TAG_OFF (IS_ENABLED(CONFIG_KASAN_GENERIC) ? 0 : KASAN_GRANULE_SIZE)
 
+static bool multishot;
+
+/* Fields set based on lines observed in the console. */
+static struct {
+       bool report_found;
+       bool async_fault;
+} test_status;
+
 /*
  * Some tests use these global variables to store return values from function
  * calls that could otherwise be eliminated by the compiler as dead code.
 void *kasan_ptr_result;
 int kasan_int_result;
 
-static struct kunit_resource resource;
-static struct kunit_kasan_status test_status;
-static bool multishot;
+/* Probe for console output: obtains test_status lines of interest. */
+static void probe_console(void *ignore, const char *buf, size_t len)
+{
+       if (strnstr(buf, "BUG: KASAN: ", len))
+               WRITE_ONCE(test_status.report_found, true);
+       else if (strnstr(buf, "Asynchronous fault: ", len))
+               WRITE_ONCE(test_status.async_fault, true);
+}
 
-/*
- * Temporarily enable multi-shot mode. Otherwise, KASAN would only report the
- * first detected bug and panic the kernel if panic_on_warn is enabled. For
- * hardware tag-based KASAN also allow tag checking to be reenabled for each
- * test, see the comment for KUNIT_EXPECT_KASAN_FAIL().
- */
-static int kasan_test_init(struct kunit *test)
+static void register_tracepoints(struct tracepoint *tp, void *ignore)
+{
+       check_trace_callback_type_console(probe_console);
+       if (!strcmp(tp->name, "console"))
+               WARN_ON(tracepoint_probe_register(tp, probe_console, NULL));
+}
+
+static void unregister_tracepoints(struct tracepoint *tp, void *ignore)
+{
+       if (!strcmp(tp->name, "console"))
+               tracepoint_probe_unregister(tp, probe_console, NULL);
+}
+
+static int kasan_suite_init(struct kunit_suite *suite)
 {
        if (!kasan_enabled()) {
-               kunit_err(test, "can't run KASAN tests with KASAN disabled");
+               pr_err("Can't run KASAN tests with KASAN disabled");
                return -1;
        }
 
+       /* Stop failing KUnit tests on KASAN reports. */
+       kasan_kunit_test_suite_start();
+
+       /*
+        * Temporarily enable multi-shot mode. Otherwise, KASAN would only
+        * report the first detected bug and panic the kernel if panic_on_warn
+        * is enabled.
+        */
        multishot = kasan_save_enable_multi_shot();
-       test_status.report_found = false;
-       test_status.sync_fault = false;
-       kunit_add_named_resource(test, NULL, NULL, &resource,
-                                       "kasan_status", &test_status);
+
+       /*
+        * Because we want to be able to build the test as a module, we need to
+        * iterate through all known tracepoints, since the static registration
+        * won't work here.
+        */
+       for_each_kernel_tracepoint(register_tracepoints, NULL);
        return 0;
 }
 
-static void kasan_test_exit(struct kunit *test)
+static void kasan_suite_exit(struct kunit_suite *suite)
 {
+       kasan_kunit_test_suite_end();
        kasan_restore_multi_shot(multishot);
-       KUNIT_EXPECT_FALSE(test, test_status.report_found);
+       for_each_kernel_tracepoint(unregister_tracepoints, NULL);
+       tracepoint_synchronize_unregister();
+}
+
+static void kasan_test_exit(struct kunit *test)
+{
+       KUNIT_EXPECT_FALSE(test, READ_ONCE(test_status.report_found));
 }
 
 /**
@@ -106,11 +147,12 @@ static void kasan_test_exit(struct kunit *test)
        if (IS_ENABLED(CONFIG_KASAN_HW_TAGS) &&                         \
            kasan_sync_fault_possible()) {                              \
                if (READ_ONCE(test_status.report_found) &&              \
-                   READ_ONCE(test_status.sync_fault))                  \
+                   !READ_ONCE(test_status.async_fault))                \
                        kasan_enable_tagging();                         \
                migrate_enable();                                       \
        }                                                               \
        WRITE_ONCE(test_status.report_found, false);                    \
+       WRITE_ONCE(test_status.async_fault, false);                     \
 } while (0)
 
 #define KASAN_TEST_NEEDS_CONFIG_ON(test, config) do {                  \
@@ -1110,6 +1152,67 @@ static void kmalloc_double_kzfree(struct kunit *test)
        KUNIT_EXPECT_KASAN_FAIL(test, kfree_sensitive(ptr));
 }
 
+/*
+ * The two tests below check that Generic KASAN prints auxiliary stack traces
+ * for RCU callbacks and workqueues. The reports need to be inspected manually.
+ *
+ * These tests are still enabled for other KASAN modes to make sure that all
+ * modes report bad accesses in tested scenarios.
+ */
+
+static struct kasan_rcu_info {
+       int i;
+       struct rcu_head rcu;
+} *global_rcu_ptr;
+
+static void rcu_uaf_reclaim(struct rcu_head *rp)
+{
+       struct kasan_rcu_info *fp =
+               container_of(rp, struct kasan_rcu_info, rcu);
+
+       kfree(fp);
+       ((volatile struct kasan_rcu_info *)fp)->i;
+}
+
+static void rcu_uaf(struct kunit *test)
+{
+       struct kasan_rcu_info *ptr;
+
+       ptr = kmalloc(sizeof(struct kasan_rcu_info), GFP_KERNEL);
+       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
+
+       global_rcu_ptr = rcu_dereference_protected(
+                               (struct kasan_rcu_info __rcu *)ptr, NULL);
+
+       KUNIT_EXPECT_KASAN_FAIL(test,
+               call_rcu(&global_rcu_ptr->rcu, rcu_uaf_reclaim);
+               rcu_barrier());
+}
+
+static void workqueue_uaf_work(struct work_struct *work)
+{
+       kfree(work);
+}
+
+static void workqueue_uaf(struct kunit *test)
+{
+       struct workqueue_struct *workqueue;
+       struct work_struct *work;
+
+       workqueue = create_workqueue("kasan_workqueue_test");
+       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, workqueue);
+
+       work = kmalloc(sizeof(struct work_struct), GFP_KERNEL);
+       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, work);
+
+       INIT_WORK(work, workqueue_uaf_work);
+       queue_work(workqueue, work);
+       destroy_workqueue(workqueue);
+
+       KUNIT_EXPECT_KASAN_FAIL(test,
+               ((volatile struct work_struct *)work)->data);
+}
+
 static void vmalloc_helpers_tags(struct kunit *test)
 {
        void *ptr;
@@ -1306,7 +1409,7 @@ static void match_all_not_assigned(struct kunit *test)
        KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
 
        for (i = 0; i < 256; i++) {
-               size = prandom_u32_max(1024) + 1;
+               size = get_random_u32_inclusive(1, 1024);
                ptr = kmalloc(size, GFP_KERNEL);
                KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
                KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN);
@@ -1315,7 +1418,7 @@ static void match_all_not_assigned(struct kunit *test)
        }
 
        for (i = 0; i < 256; i++) {
-               order = prandom_u32_max(4) + 1;
+               order = get_random_u32_inclusive(1, 4);
                pages = alloc_pages(GFP_KERNEL, order);
                ptr = page_address(pages);
                KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
@@ -1328,7 +1431,7 @@ static void match_all_not_assigned(struct kunit *test)
                return;
 
        for (i = 0; i < 256; i++) {
-               size = prandom_u32_max(1024) + 1;
+               size = get_random_u32_inclusive(1, 1024);
                ptr = vmalloc(size);
                KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
                KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN);
@@ -1441,6 +1544,8 @@ static struct kunit_case kasan_kunit_test_cases[] = {
        KUNIT_CASE(kasan_bitops_generic),
        KUNIT_CASE(kasan_bitops_tags),
        KUNIT_CASE(kmalloc_double_kzfree),
+       KUNIT_CASE(rcu_uaf),
+       KUNIT_CASE(workqueue_uaf),
        KUNIT_CASE(vmalloc_helpers_tags),
        KUNIT_CASE(vmalloc_oob),
        KUNIT_CASE(vmap_tags),
@@ -1454,9 +1559,10 @@ static struct kunit_case kasan_kunit_test_cases[] = {
 
 static struct kunit_suite kasan_kunit_test_suite = {
        .name = "kasan",
-       .init = kasan_test_init,
        .test_cases = kasan_kunit_test_cases,
        .exit = kasan_test_exit,
+       .suite_init = kasan_suite_init,
+       .suite_exit = kasan_suite_exit,
 };
 
 kunit_test_suite(kasan_kunit_test_suite);