1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * This is for all the tests related to logic bugs (e.g. bad dereferences, 4 * bad alignment, bad loops, bad locking, bad scheduling, deep stacks, and 5 * lockups) along with other things that don't fit well into existing LKDTM 6 * test source files. 7 */ 8 #include "lkdtm.h" 9 #include <linux/cpu.h> 10 #include <linux/list.h> 11 #include <linux/hrtimer.h> 12 #include <linux/sched.h> 13 #include <linux/sched/signal.h> 14 #include <linux/sched/task_stack.h> 15 #include <linux/slab.h> 16 #include <linux/stop_machine.h> 17 #include <linux/uaccess.h> 18 19 #if IS_ENABLED(CONFIG_X86_32) && !IS_ENABLED(CONFIG_UML) 20 #include <asm/desc.h> 21 #endif 22 23 struct lkdtm_list { 24 struct list_head node; 25 }; 26 27 /* 28 * Make sure our attempts to over run the kernel stack doesn't trigger 29 * a compiler warning when CONFIG_FRAME_WARN is set. Then make sure we 30 * recurse past the end of THREAD_SIZE by default. 31 */ 32 #if defined(CONFIG_FRAME_WARN) && (CONFIG_FRAME_WARN > 0) 33 #define REC_STACK_SIZE (_AC(CONFIG_FRAME_WARN, UL) / 2) 34 #else 35 #define REC_STACK_SIZE (THREAD_SIZE / 8UL) 36 #endif 37 #define REC_NUM_DEFAULT ((THREAD_SIZE / REC_STACK_SIZE) * 2) 38 39 static int recur_count = REC_NUM_DEFAULT; 40 41 static DEFINE_SPINLOCK(lock_me_up); 42 43 /* 44 * Make sure compiler does not optimize this function or stack frame away: 45 * - function marked noinline 46 * - stack variables are marked volatile 47 * - stack variables are written (memset()) and read (buf[..] passed as arg) 48 * - function may have external effects (memzero_explicit()) 49 * - no tail recursion possible 50 */ 51 static int noinline recursive_loop(int remaining) 52 { 53 volatile char buf[REC_STACK_SIZE]; 54 volatile int ret; 55 56 memset((void *)buf, remaining & 0xFF, sizeof(buf)); 57 if (!remaining) 58 ret = 0; 59 else 60 ret = recursive_loop((int)buf[remaining % sizeof(buf)] - 1); 61 memzero_explicit((void *)buf, sizeof(buf)); 62 return ret; 63 } 64 65 /* If the depth is negative, use the default, otherwise keep parameter. */ 66 void __init lkdtm_bugs_init(int *recur_param) 67 { 68 if (*recur_param < 0) 69 *recur_param = recur_count; 70 else 71 recur_count = *recur_param; 72 } 73 74 static void lkdtm_PANIC(void) 75 { 76 panic("dumptest"); 77 } 78 79 static int panic_stop_irqoff_fn(void *arg) 80 { 81 atomic_t *v = arg; 82 83 /* 84 * As stop_machine() disables interrupts, all CPUs within this function 85 * have interrupts disabled and cannot take a regular IPI. 86 * 87 * The last CPU which enters here will trigger a panic, and as all CPUs 88 * cannot take a regular IPI, we'll only be able to stop secondaries if 89 * smp_send_stop() or crash_smp_send_stop() uses an NMI. 90 */ 91 if (atomic_inc_return(v) == num_online_cpus()) 92 panic("panic stop irqoff test"); 93 94 for (;;) 95 cpu_relax(); 96 } 97 98 static void lkdtm_PANIC_STOP_IRQOFF(void) 99 { 100 atomic_t v = ATOMIC_INIT(0); 101 stop_machine(panic_stop_irqoff_fn, &v, cpu_online_mask); 102 } 103 104 static bool wait_for_panic; 105 106 static enum hrtimer_restart panic_in_hardirq(struct hrtimer *timer) 107 { 108 panic("from hard IRQ context"); 109 110 wait_for_panic = false; 111 return HRTIMER_NORESTART; 112 } 113 114 static void lkdtm_PANIC_IN_HARDIRQ(void) 115 { 116 struct hrtimer timer; 117 118 wait_for_panic = true; 119 hrtimer_setup_on_stack(&timer, panic_in_hardirq, 120 CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD); 121 hrtimer_start(&timer, us_to_ktime(100), HRTIMER_MODE_REL_HARD); 122 123 while (READ_ONCE(wait_for_panic)) 124 cpu_relax(); 125 126 hrtimer_cancel(&timer); 127 } 128 129 static void lkdtm_BUG(void) 130 { 131 BUG(); 132 } 133 134 static bool wait_for_bug; 135 136 static enum hrtimer_restart bug_in_hardirq(struct hrtimer *timer) 137 { 138 BUG(); 139 140 wait_for_bug = false; 141 return HRTIMER_NORESTART; 142 } 143 144 static void lkdtm_BUG_IN_HARDIRQ(void) 145 { 146 struct hrtimer timer; 147 148 wait_for_bug = true; 149 hrtimer_setup_on_stack(&timer, bug_in_hardirq, 150 CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD); 151 hrtimer_start(&timer, us_to_ktime(100), HRTIMER_MODE_REL_HARD); 152 153 while (READ_ONCE(wait_for_bug)) 154 cpu_relax(); 155 156 hrtimer_cancel(&timer); 157 } 158 159 static int warn_counter; 160 161 static void lkdtm_WARNING(void) 162 { 163 WARN_ON(++warn_counter); 164 } 165 166 static void lkdtm_WARNING_MESSAGE(void) 167 { 168 WARN(1, "Warning message trigger count: %d\n", ++warn_counter); 169 } 170 171 static void lkdtm_EXCEPTION(void) 172 { 173 *((volatile int *) 0) = 0; 174 } 175 176 static void lkdtm_LOOP(void) 177 { 178 for (;;) 179 ; 180 } 181 182 static void lkdtm_EXHAUST_STACK(void) 183 { 184 pr_info("Calling function with %lu frame size to depth %d ...\n", 185 REC_STACK_SIZE, recur_count); 186 recursive_loop(recur_count); 187 pr_info("FAIL: survived without exhausting stack?!\n"); 188 } 189 190 static noinline void __lkdtm_CORRUPT_STACK(void *stack) 191 { 192 memset(stack, '\xff', 64); 193 } 194 195 /* This should trip the stack canary, not corrupt the return address. */ 196 static noinline void lkdtm_CORRUPT_STACK(void) 197 { 198 /* Use default char array length that triggers stack protection. */ 199 char data[8] __aligned(sizeof(void *)); 200 201 pr_info("Corrupting stack containing char array ...\n"); 202 __lkdtm_CORRUPT_STACK((void *)&data); 203 } 204 205 /* Same as above but will only get a canary with -fstack-protector-strong */ 206 static noinline void lkdtm_CORRUPT_STACK_STRONG(void) 207 { 208 union { 209 unsigned short shorts[4]; 210 unsigned long *ptr; 211 } data __aligned(sizeof(void *)); 212 213 pr_info("Corrupting stack containing union ...\n"); 214 __lkdtm_CORRUPT_STACK((void *)&data); 215 } 216 217 static pid_t stack_pid; 218 static unsigned long stack_addr; 219 220 static void lkdtm_REPORT_STACK(void) 221 { 222 volatile uintptr_t magic; 223 pid_t pid = task_pid_nr(current); 224 225 if (pid != stack_pid) { 226 pr_info("Starting stack offset tracking for pid %d\n", pid); 227 stack_pid = pid; 228 stack_addr = (uintptr_t)&magic; 229 } 230 231 pr_info("Stack offset: %d\n", (int)(stack_addr - (uintptr_t)&magic)); 232 } 233 234 static pid_t stack_canary_pid; 235 static unsigned long stack_canary; 236 static unsigned long stack_canary_offset; 237 238 static noinline void __lkdtm_REPORT_STACK_CANARY(void *stack) 239 { 240 int i = 0; 241 pid_t pid = task_pid_nr(current); 242 unsigned long *canary = (unsigned long *)stack; 243 unsigned long current_offset = 0, init_offset = 0; 244 245 /* Do our best to find the canary in a 16 word window ... */ 246 for (i = 1; i < 16; i++) { 247 canary = (unsigned long *)stack + i; 248 #ifdef CONFIG_STACKPROTECTOR 249 if (*canary == current->stack_canary) 250 current_offset = i; 251 if (*canary == init_task.stack_canary) 252 init_offset = i; 253 #endif 254 } 255 256 if (current_offset == 0) { 257 /* 258 * If the canary doesn't match what's in the task_struct, 259 * we're either using a global canary or the stack frame 260 * layout changed. 261 */ 262 if (init_offset != 0) { 263 pr_err("FAIL: global stack canary found at offset %ld (canary for pid %d matches init_task's)!\n", 264 init_offset, pid); 265 } else { 266 pr_warn("FAIL: did not correctly locate stack canary :(\n"); 267 pr_expected_config(CONFIG_STACKPROTECTOR); 268 } 269 270 return; 271 } else if (init_offset != 0) { 272 pr_warn("WARNING: found both current and init_task canaries nearby?!\n"); 273 } 274 275 canary = (unsigned long *)stack + current_offset; 276 if (stack_canary_pid == 0) { 277 stack_canary = *canary; 278 stack_canary_pid = pid; 279 stack_canary_offset = current_offset; 280 pr_info("Recorded stack canary for pid %d at offset %ld\n", 281 stack_canary_pid, stack_canary_offset); 282 } else if (pid == stack_canary_pid) { 283 pr_warn("ERROR: saw pid %d again -- please use a new pid\n", pid); 284 } else { 285 if (current_offset != stack_canary_offset) { 286 pr_warn("ERROR: canary offset changed from %ld to %ld!?\n", 287 stack_canary_offset, current_offset); 288 return; 289 } 290 291 if (*canary == stack_canary) { 292 pr_warn("FAIL: canary identical for pid %d and pid %d at offset %ld!\n", 293 stack_canary_pid, pid, current_offset); 294 } else { 295 pr_info("ok: stack canaries differ between pid %d and pid %d at offset %ld.\n", 296 stack_canary_pid, pid, current_offset); 297 /* Reset the test. */ 298 stack_canary_pid = 0; 299 } 300 } 301 } 302 303 static void lkdtm_REPORT_STACK_CANARY(void) 304 { 305 /* Use default char array length that triggers stack protection. */ 306 char data[8] __aligned(sizeof(void *)) = { }; 307 308 __lkdtm_REPORT_STACK_CANARY((void *)&data); 309 } 310 311 static void lkdtm_UNALIGNED_LOAD_STORE_WRITE(void) 312 { 313 static u8 data[5] __attribute__((aligned(4))) = {1, 2, 3, 4, 5}; 314 u32 *p; 315 u32 val = 0x12345678; 316 317 p = (u32 *)(data + 1); 318 if (*p == 0) 319 val = 0x87654321; 320 *p = val; 321 322 if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) 323 pr_err("XFAIL: arch has CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS\n"); 324 } 325 326 static void lkdtm_SOFTLOCKUP(void) 327 { 328 preempt_disable(); 329 for (;;) 330 cpu_relax(); 331 } 332 333 static void lkdtm_HARDLOCKUP(void) 334 { 335 local_irq_disable(); 336 for (;;) 337 cpu_relax(); 338 } 339 340 static void __lkdtm_SMP_CALL_LOCKUP(void *unused) 341 { 342 for (;;) 343 cpu_relax(); 344 } 345 346 static void lkdtm_SMP_CALL_LOCKUP(void) 347 { 348 unsigned int cpu, target; 349 350 cpus_read_lock(); 351 352 cpu = get_cpu(); 353 target = cpumask_any_but(cpu_online_mask, cpu); 354 355 if (target >= nr_cpu_ids) { 356 pr_err("FAIL: no other online CPUs\n"); 357 goto out_put_cpus; 358 } 359 360 smp_call_function_single(target, __lkdtm_SMP_CALL_LOCKUP, NULL, 1); 361 362 pr_err("FAIL: did not hang\n"); 363 364 out_put_cpus: 365 put_cpu(); 366 cpus_read_unlock(); 367 } 368 369 static void lkdtm_SPINLOCKUP(void) 370 { 371 /* Must be called twice to trigger. */ 372 spin_lock(&lock_me_up); 373 /* Let sparse know we intended to exit holding the lock. */ 374 __release(&lock_me_up); 375 } 376 377 static void __noreturn lkdtm_HUNG_TASK(void) 378 { 379 set_current_state(TASK_UNINTERRUPTIBLE); 380 schedule(); 381 BUG(); 382 } 383 384 static volatile unsigned int huge = INT_MAX - 2; 385 static volatile unsigned int ignored; 386 387 static void lkdtm_OVERFLOW_SIGNED(void) 388 { 389 int value; 390 391 value = huge; 392 pr_info("Normal signed addition ...\n"); 393 value += 1; 394 ignored = value; 395 396 pr_info("Overflowing signed addition ...\n"); 397 value += 4; 398 ignored = value; 399 } 400 401 402 static void lkdtm_OVERFLOW_UNSIGNED(void) 403 { 404 unsigned int value; 405 406 value = huge; 407 pr_info("Normal unsigned addition ...\n"); 408 value += 1; 409 ignored = value; 410 411 pr_info("Overflowing unsigned addition ...\n"); 412 value += 4; 413 ignored = value; 414 } 415 416 /* Intentionally using unannotated flex array definition. */ 417 struct array_bounds_flex_array { 418 int one; 419 int two; 420 char data[]; 421 }; 422 423 struct array_bounds { 424 int one; 425 int two; 426 char data[8]; 427 int three; 428 }; 429 430 static void lkdtm_ARRAY_BOUNDS(void) 431 { 432 struct array_bounds_flex_array *not_checked; 433 struct array_bounds *checked; 434 volatile int i; 435 436 not_checked = kmalloc(sizeof(*not_checked) * 2, GFP_KERNEL); 437 checked = kmalloc(sizeof(*checked) * 2, GFP_KERNEL); 438 if (!not_checked || !checked) { 439 kfree(not_checked); 440 kfree(checked); 441 return; 442 } 443 444 pr_info("Array access within bounds ...\n"); 445 /* For both, touch all bytes in the actual member size. */ 446 for (i = 0; i < sizeof(checked->data); i++) 447 checked->data[i] = 'A'; 448 /* 449 * For the uninstrumented flex array member, also touch 1 byte 450 * beyond to verify it is correctly uninstrumented. 451 */ 452 for (i = 0; i < 2; i++) 453 not_checked->data[i] = 'A'; 454 455 pr_info("Array access beyond bounds ...\n"); 456 for (i = 0; i < sizeof(checked->data) + 1; i++) 457 checked->data[i] = 'B'; 458 459 kfree(not_checked); 460 kfree(checked); 461 pr_err("FAIL: survived array bounds overflow!\n"); 462 if (IS_ENABLED(CONFIG_UBSAN_BOUNDS)) 463 pr_expected_config(CONFIG_UBSAN_TRAP); 464 else 465 pr_expected_config(CONFIG_UBSAN_BOUNDS); 466 } 467 468 struct lkdtm_annotated { 469 unsigned long flags; 470 int count; 471 int array[] __counted_by(count); 472 }; 473 474 static volatile int fam_count = 4; 475 476 static void lkdtm_FAM_BOUNDS(void) 477 { 478 struct lkdtm_annotated *inst; 479 480 inst = kzalloc(struct_size(inst, array, fam_count + 1), GFP_KERNEL); 481 if (!inst) { 482 pr_err("FAIL: could not allocate test struct!\n"); 483 return; 484 } 485 486 inst->count = fam_count; 487 pr_info("Array access within bounds ...\n"); 488 inst->array[1] = fam_count; 489 ignored = inst->array[1]; 490 491 pr_info("Array access beyond bounds ...\n"); 492 inst->array[fam_count] = fam_count; 493 ignored = inst->array[fam_count]; 494 495 kfree(inst); 496 497 pr_err("FAIL: survived access of invalid flexible array member index!\n"); 498 499 if (!IS_ENABLED(CONFIG_CC_HAS_COUNTED_BY)) 500 pr_warn("This is expected since this %s was built with a compiler that does not support __counted_by\n", 501 lkdtm_kernel_info); 502 else if (IS_ENABLED(CONFIG_UBSAN_BOUNDS)) 503 pr_expected_config(CONFIG_UBSAN_TRAP); 504 else 505 pr_expected_config(CONFIG_UBSAN_BOUNDS); 506 } 507 508 static void lkdtm_CORRUPT_LIST_ADD(void) 509 { 510 /* 511 * Initially, an empty list via LIST_HEAD: 512 * test_head.next = &test_head 513 * test_head.prev = &test_head 514 */ 515 LIST_HEAD(test_head); 516 struct lkdtm_list good, bad; 517 void *target[2] = { }; 518 void *redirection = ⌖ 519 520 pr_info("attempting good list addition\n"); 521 522 /* 523 * Adding to the list performs these actions: 524 * test_head.next->prev = &good.node 525 * good.node.next = test_head.next 526 * good.node.prev = test_head 527 * test_head.next = good.node 528 */ 529 list_add(&good.node, &test_head); 530 531 pr_info("attempting corrupted list addition\n"); 532 /* 533 * In simulating this "write what where" primitive, the "what" is 534 * the address of &bad.node, and the "where" is the address held 535 * by "redirection". 536 */ 537 test_head.next = redirection; 538 list_add(&bad.node, &test_head); 539 540 if (target[0] == NULL && target[1] == NULL) 541 pr_err("Overwrite did not happen, but no BUG?!\n"); 542 else { 543 pr_err("list_add() corruption not detected!\n"); 544 pr_expected_config(CONFIG_LIST_HARDENED); 545 } 546 } 547 548 static void lkdtm_CORRUPT_LIST_DEL(void) 549 { 550 LIST_HEAD(test_head); 551 struct lkdtm_list item; 552 void *target[2] = { }; 553 void *redirection = ⌖ 554 555 list_add(&item.node, &test_head); 556 557 pr_info("attempting good list removal\n"); 558 list_del(&item.node); 559 560 pr_info("attempting corrupted list removal\n"); 561 list_add(&item.node, &test_head); 562 563 /* As with the list_add() test above, this corrupts "next". */ 564 item.node.next = redirection; 565 list_del(&item.node); 566 567 if (target[0] == NULL && target[1] == NULL) 568 pr_err("Overwrite did not happen, but no BUG?!\n"); 569 else { 570 pr_err("list_del() corruption not detected!\n"); 571 pr_expected_config(CONFIG_LIST_HARDENED); 572 } 573 } 574 575 /* Test that VMAP_STACK is actually allocating with a leading guard page */ 576 static void lkdtm_STACK_GUARD_PAGE_LEADING(void) 577 { 578 const unsigned char *stack = task_stack_page(current); 579 const unsigned char *ptr = stack - 1; 580 volatile unsigned char byte; 581 582 pr_info("attempting bad read from page below current stack\n"); 583 584 byte = *ptr; 585 586 pr_err("FAIL: accessed page before stack! (byte: %x)\n", byte); 587 } 588 589 /* Test that VMAP_STACK is actually allocating with a trailing guard page */ 590 static void lkdtm_STACK_GUARD_PAGE_TRAILING(void) 591 { 592 const unsigned char *stack = task_stack_page(current); 593 const unsigned char *ptr = stack + THREAD_SIZE; 594 volatile unsigned char byte; 595 596 pr_info("attempting bad read from page above current stack\n"); 597 598 byte = *ptr; 599 600 pr_err("FAIL: accessed page after stack! (byte: %x)\n", byte); 601 } 602 603 static void lkdtm_UNSET_SMEP(void) 604 { 605 #if IS_ENABLED(CONFIG_X86_64) && !IS_ENABLED(CONFIG_UML) 606 #define MOV_CR4_DEPTH 64 607 void (*direct_write_cr4)(unsigned long val); 608 unsigned char *insn; 609 unsigned long cr4; 610 int i; 611 612 cr4 = native_read_cr4(); 613 614 if ((cr4 & X86_CR4_SMEP) != X86_CR4_SMEP) { 615 pr_err("FAIL: SMEP not in use\n"); 616 return; 617 } 618 cr4 &= ~(X86_CR4_SMEP); 619 620 pr_info("trying to clear SMEP normally\n"); 621 native_write_cr4(cr4); 622 if (cr4 == native_read_cr4()) { 623 pr_err("FAIL: pinning SMEP failed!\n"); 624 cr4 |= X86_CR4_SMEP; 625 pr_info("restoring SMEP\n"); 626 native_write_cr4(cr4); 627 return; 628 } 629 pr_info("ok: SMEP did not get cleared\n"); 630 631 /* 632 * To test the post-write pinning verification we need to call 633 * directly into the middle of native_write_cr4() where the 634 * cr4 write happens, skipping any pinning. This searches for 635 * the cr4 writing instruction. 636 */ 637 insn = (unsigned char *)native_write_cr4; 638 OPTIMIZER_HIDE_VAR(insn); 639 for (i = 0; i < MOV_CR4_DEPTH; i++) { 640 /* mov %rdi, %cr4 */ 641 if (insn[i] == 0x0f && insn[i+1] == 0x22 && insn[i+2] == 0xe7) 642 break; 643 /* mov %rdi,%rax; mov %rax, %cr4 */ 644 if (insn[i] == 0x48 && insn[i+1] == 0x89 && 645 insn[i+2] == 0xf8 && insn[i+3] == 0x0f && 646 insn[i+4] == 0x22 && insn[i+5] == 0xe0) 647 break; 648 } 649 if (i >= MOV_CR4_DEPTH) { 650 pr_info("ok: cannot locate cr4 writing call gadget\n"); 651 return; 652 } 653 direct_write_cr4 = (void *)(insn + i); 654 655 pr_info("trying to clear SMEP with call gadget\n"); 656 direct_write_cr4(cr4); 657 if (native_read_cr4() & X86_CR4_SMEP) { 658 pr_info("ok: SMEP removal was reverted\n"); 659 } else { 660 pr_err("FAIL: cleared SMEP not detected!\n"); 661 cr4 |= X86_CR4_SMEP; 662 pr_info("restoring SMEP\n"); 663 native_write_cr4(cr4); 664 } 665 #else 666 pr_err("XFAIL: this test is x86_64-only\n"); 667 #endif 668 } 669 670 static void lkdtm_DOUBLE_FAULT(void) 671 { 672 #if IS_ENABLED(CONFIG_X86_32) && !IS_ENABLED(CONFIG_UML) 673 /* 674 * Trigger #DF by setting the stack limit to zero. This clobbers 675 * a GDT TLS slot, which is okay because the current task will die 676 * anyway due to the double fault. 677 */ 678 struct desc_struct d = { 679 .type = 3, /* expand-up, writable, accessed data */ 680 .p = 1, /* present */ 681 .d = 1, /* 32-bit */ 682 .g = 0, /* limit in bytes */ 683 .s = 1, /* not system */ 684 }; 685 686 local_irq_disable(); 687 write_gdt_entry(get_cpu_gdt_rw(smp_processor_id()), 688 GDT_ENTRY_TLS_MIN, &d, DESCTYPE_S); 689 690 /* 691 * Put our zero-limit segment in SS and then trigger a fault. The 692 * 4-byte access to (%esp) will fault with #SS, and the attempt to 693 * deliver the fault will recursively cause #SS and result in #DF. 694 * This whole process happens while NMIs and MCEs are blocked by the 695 * MOV SS window. This is nice because an NMI with an invalid SS 696 * would also double-fault, resulting in the NMI or MCE being lost. 697 */ 698 asm volatile ("movw %0, %%ss; addl $0, (%%esp)" :: 699 "r" ((unsigned short)(GDT_ENTRY_TLS_MIN << 3))); 700 701 pr_err("FAIL: tried to double fault but didn't die\n"); 702 #else 703 pr_err("XFAIL: this test is ia32-only\n"); 704 #endif 705 } 706 707 #ifdef CONFIG_ARM64 708 static noinline void change_pac_parameters(void) 709 { 710 if (IS_ENABLED(CONFIG_ARM64_PTR_AUTH_KERNEL)) { 711 /* Reset the keys of current task */ 712 ptrauth_thread_init_kernel(current); 713 ptrauth_thread_switch_kernel(current); 714 } 715 } 716 #endif 717 718 static noinline void lkdtm_CORRUPT_PAC(void) 719 { 720 #ifdef CONFIG_ARM64 721 #define CORRUPT_PAC_ITERATE 10 722 int i; 723 724 if (!IS_ENABLED(CONFIG_ARM64_PTR_AUTH_KERNEL)) 725 pr_err("FAIL: kernel not built with CONFIG_ARM64_PTR_AUTH_KERNEL\n"); 726 727 if (!system_supports_address_auth()) { 728 pr_err("FAIL: CPU lacks pointer authentication feature\n"); 729 return; 730 } 731 732 pr_info("changing PAC parameters to force function return failure...\n"); 733 /* 734 * PAC is a hash value computed from input keys, return address and 735 * stack pointer. As pac has fewer bits so there is a chance of 736 * collision, so iterate few times to reduce the collision probability. 737 */ 738 for (i = 0; i < CORRUPT_PAC_ITERATE; i++) 739 change_pac_parameters(); 740 741 pr_err("FAIL: survived PAC changes! Kernel may be unstable from here\n"); 742 #else 743 pr_err("XFAIL: this test is arm64-only\n"); 744 #endif 745 } 746 747 static struct crashtype crashtypes[] = { 748 CRASHTYPE(PANIC), 749 CRASHTYPE(PANIC_STOP_IRQOFF), 750 CRASHTYPE(PANIC_IN_HARDIRQ), 751 CRASHTYPE(BUG), 752 CRASHTYPE(BUG_IN_HARDIRQ), 753 CRASHTYPE(WARNING), 754 CRASHTYPE(WARNING_MESSAGE), 755 CRASHTYPE(EXCEPTION), 756 CRASHTYPE(LOOP), 757 CRASHTYPE(EXHAUST_STACK), 758 CRASHTYPE(CORRUPT_STACK), 759 CRASHTYPE(CORRUPT_STACK_STRONG), 760 CRASHTYPE(REPORT_STACK), 761 CRASHTYPE(REPORT_STACK_CANARY), 762 CRASHTYPE(UNALIGNED_LOAD_STORE_WRITE), 763 CRASHTYPE(SOFTLOCKUP), 764 CRASHTYPE(HARDLOCKUP), 765 CRASHTYPE(SMP_CALL_LOCKUP), 766 CRASHTYPE(SPINLOCKUP), 767 CRASHTYPE(HUNG_TASK), 768 CRASHTYPE(OVERFLOW_SIGNED), 769 CRASHTYPE(OVERFLOW_UNSIGNED), 770 CRASHTYPE(ARRAY_BOUNDS), 771 CRASHTYPE(FAM_BOUNDS), 772 CRASHTYPE(CORRUPT_LIST_ADD), 773 CRASHTYPE(CORRUPT_LIST_DEL), 774 CRASHTYPE(STACK_GUARD_PAGE_LEADING), 775 CRASHTYPE(STACK_GUARD_PAGE_TRAILING), 776 CRASHTYPE(UNSET_SMEP), 777 CRASHTYPE(DOUBLE_FAULT), 778 CRASHTYPE(CORRUPT_PAC), 779 }; 780 781 struct crashtype_category bugs_crashtypes = { 782 .crashtypes = crashtypes, 783 .len = ARRAY_SIZE(crashtypes), 784 }; 785