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#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;
}
void
test_double_free_pre(void) {
safety_check_set_abort(&fake_abort);
fake_abort_called = false;
}
void
test_double_free_post() {
expect_b_eq(fake_abort_called, true, "Double-free check didn't fire.");
safety_check_set_abort(NULL);
}
bool tcache_enabled() {
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);
}
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