#include "test/jemalloc_test.h" #include "test/san.h" #include "jemalloc/internal/safety_check.h" bool fake_abort_called; void fake_abort(const char *message) { (void)message; fake_abort_called = true; } static void test_double_free_pre(void) { safety_check_set_abort(&fake_abort); fake_abort_called = false; } static void test_double_free_post(void) { expect_b_eq(fake_abort_called, true, "Double-free check didn't fire."); safety_check_set_abort(NULL); } static bool tcache_enabled(void) { bool enabled; size_t sz = sizeof(enabled); assert_d_eq( mallctl("thread.tcache.enabled", &enabled, &sz, NULL, 0), 0, "Unexpected mallctl failure"); return enabled; } TEST_BEGIN(test_large_double_free_tcache) { test_skip_if(!config_opt_safety_checks); /* * Skip debug builds, since too many assertions will be triggered with * double-free before hitting the one we are interested in. */ test_skip_if(config_debug); test_double_free_pre(); char *ptr = malloc(SC_LARGE_MINCLASS); bool guarded = extent_is_guarded(tsdn_fetch(), ptr); free(ptr); if (!guarded) { free(ptr); } else { /* * Skip because guarded extents may unguard immediately on * deallocation, in which case the second free will crash before * reaching the intended safety check. */ fake_abort_called = true; } mallctl("thread.tcache.flush", NULL, NULL, NULL, 0); test_double_free_post(); } TEST_END TEST_BEGIN(test_large_double_free_no_tcache) { test_skip_if(!config_opt_safety_checks); test_skip_if(config_debug); test_double_free_pre(); char *ptr = mallocx(SC_LARGE_MINCLASS, MALLOCX_TCACHE_NONE); bool guarded = extent_is_guarded(tsdn_fetch(), ptr); dallocx(ptr, MALLOCX_TCACHE_NONE); if (!guarded) { dallocx(ptr, MALLOCX_TCACHE_NONE); } else { /* * Skip because guarded extents may unguard immediately on * deallocation, in which case the second free will crash before * reaching the intended safety check. */ fake_abort_called = true; } test_double_free_post(); } TEST_END TEST_BEGIN(test_small_double_free_tcache) { test_skip_if(!config_debug); test_skip_if(opt_debug_double_free_max_scan == 0); test_skip_if(!tcache_enabled()); test_double_free_pre(); char *ptr = malloc(1); bool guarded = extent_is_guarded(tsdn_fetch(), ptr); free(ptr); if (!guarded) { free(ptr); } else { /* * Skip because guarded extents may unguard immediately on * deallocation, in which case the second free will crash before * reaching the intended safety check. */ fake_abort_called = true; } mallctl("thread.tcache.flush", NULL, NULL, NULL, 0); test_double_free_post(); } TEST_END TEST_BEGIN(test_small_double_free_arena) { test_skip_if(!config_debug); test_skip_if(!tcache_enabled()); test_double_free_pre(); /* * Allocate one more pointer to keep the slab partially used after * flushing the cache. */ char *ptr1 = malloc(1); char *ptr = malloc(1); bool guarded = extent_is_guarded(tsdn_fetch(), ptr); free(ptr); if (!guarded) { mallctl("thread.tcache.flush", NULL, NULL, NULL, 0); free(ptr); } else { /* * Skip because guarded extents may unguard immediately on * deallocation, in which case the second free will crash before * reaching the intended safety check. */ fake_abort_called = true; } test_double_free_post(); free(ptr1); } TEST_END int main(void) { return test( test_large_double_free_no_tcache, test_large_double_free_tcache, test_small_double_free_tcache, test_small_double_free_arena); }