// https://syzkaller.appspot.com/bug?id=9ca8d72c9e3925d070cb129169b482e1ad1be2ad // autogenerated by syzkaller (https://github.com/google/syzkaller) #define _GNU_SOURCE #include #include #include #include #include #include #include #include #include #include #include #include #include #include static bool write_file(const char* file, const char* what, ...) { char buf[1024]; va_list args; va_start(args, what); vsnprintf(buf, sizeof(buf), what, args); va_end(args); buf[sizeof(buf) - 1] = 0; int len = strlen(buf); int fd = open(file, O_WRONLY | O_CLOEXEC); if (fd == -1) return false; if (write(fd, buf, len) != len) { int err = errno; close(fd); errno = err; return false; } close(fd); return true; } static int inject_fault(int nth) { int fd; fd = open("/proc/thread-self/fail-nth", O_RDWR); if (fd == -1) exit(1); char buf[16]; sprintf(buf, "%d", nth); if (write(fd, buf, strlen(buf)) != (ssize_t)strlen(buf)) exit(1); return fd; } static const char* setup_fault() { int fd = open("/proc/self/make-it-fail", O_WRONLY); if (fd == -1) return "CONFIG_FAULT_INJECTION is not enabled"; close(fd); fd = open("/proc/thread-self/fail-nth", O_WRONLY); if (fd == -1) return "kernel does not have systematic fault injection support"; close(fd); static struct { const char* file; const char* val; bool fatal; } files[] = { {"/sys/kernel/debug/failslab/ignore-gfp-wait", "N", true}, {"/sys/kernel/debug/fail_futex/ignore-private", "N", false}, {"/sys/kernel/debug/fail_page_alloc/ignore-gfp-highmem", "N", false}, {"/sys/kernel/debug/fail_page_alloc/ignore-gfp-wait", "N", false}, {"/sys/kernel/debug/fail_page_alloc/min-order", "0", false}, }; unsigned i; for (i = 0; i < sizeof(files) / sizeof(files[0]); i++) { if (!write_file(files[i].file, files[i].val)) { if (files[i].fatal) return "failed to write fault injection file"; } } return NULL; } uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff}; int main(void) { syscall(__NR_mmap, /*addr=*/0x1ffffffff000ul, /*len=*/0x1000, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x200000000000ul, /*len=*/0x1000000, /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/ 7ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x200001000000ul, /*len=*/0x1000, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul); const char* reason; (void)reason; if ((reason = setup_fault())) { fprintf(stderr, "reproducer setup failed: fault injection: %s\n", reason); exit(1); } intptr_t res = 0; if (write(1, "executing program\n", sizeof("executing program\n") - 1)) { } // mkdir arguments: [ // path: ptr[in, buffer] { // buffer: {2e 2f 73 79 73 00} (length 0x6) // } // mode: open_mode = 0x1ff (8 bytes) // ] memcpy((void*)0x200000000000, "./sys\000", 6); syscall( __NR_mkdir, /*path=*/0x200000000000ul, /*mode=S_IXOTH|S_IWOTH|S_IROTH|S_IXGRP|S_IWGRP|S_IRGRP|S_IXUSR|S_IWUSR|0x100*/ 0x1fful); // mount arguments: [ // src: nil // dst: ptr[in, buffer] { // buffer: {2e 2f 73 79 73 00} (length 0x6) // } // type: ptr[in, buffer] { // buffer: {73 79 73 66 73 00} (length 0x6) // } // flags: mount_flags = 0x0 (8 bytes) // data: nil // ] memcpy((void*)0x200000000100, "./sys\000", 6); memcpy((void*)0x200000000200, "sysfs\000", 6); syscall(__NR_mount, /*src=*/0ul, /*dst=*/0x200000000100ul, /*type=*/0x200000000200ul, /*flags=*/0ul, /*data=*/0ul); // openat arguments: [ // fd: fd_dir (resource) // file: ptr[in, buffer] { // buffer: {2e 2f 73 79 73 2f 62 75 73 2f 70 63 69 2f 64 65 76 69 63 65 // 73 2f 30 30 30 30 3a 30 30 3a 31 64 2e 30 2f 72 65 6d 6f 76 65 00} // (length 0x2a) // } // flags: open_flags = 0x1 (4 bytes) // mode: open_mode = 0x0 (2 bytes) // ] // returns fd memcpy((void*)0x200000000300, "./sys/bus/pci/devices/0000:00:1d.0/remove\000", 42); res = syscall(__NR_openat, /*fd=*/0xffffff9c, /*file=*/0x200000000300ul, /*flags=O_WRONLY*/ 1, /*mode=*/0); if (res != -1) r[0] = res; // write arguments: [ // fd: fd (resource) // buf: ptr[in, buffer] { // buffer: {31} (length 0x1) // } // count: len = 0x1 (8 bytes) // ] memset((void*)0x200000000400, 49, 1); syscall(__NR_write, /*fd=*/r[0], /*buf=*/0x200000000400ul, /*count=*/1ul); // openat arguments: [ // fd: fd_dir (resource) // file: ptr[in, buffer] { // buffer: {2e 2f 73 79 73 2f 62 75 73 2f 70 63 69 2f 72 65 73 63 61 6e // 00} (length 0x15) // } // flags: open_flags = 0x1 (4 bytes) // mode: open_mode = 0x0 (2 bytes) // ] // returns fd memcpy((void*)0x200000000700, "./sys/bus/pci/rescan\000", 21); res = syscall(__NR_openat, /*fd=*/0xffffff9c, /*file=*/0x200000000700ul, /*flags=O_WRONLY*/ 1, /*mode=*/0); if (res != -1) r[1] = res; // write arguments: [ // fd: fd (resource) // buf: ptr[in, buffer] { // buffer: {31} (length 0x1) // } // count: len = 0x1 (8 bytes) // ] memset((void*)0x200000000800, 49, 1); inject_fault(4); syscall(__NR_write, /*fd=*/r[1], /*buf=*/0x200000000800ul, /*count=*/1ul); return 0; }