// https://syzkaller.appspot.com/bug?id=408ae7c8a4162a0cc35da0b0a6d252851c487a7e // 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 #include #include #include #include #include #include #include #ifndef __NR_bpf #define __NR_bpf 321 #endif static unsigned long long procid; static __thread int clone_ongoing; static __thread int skip_segv; static __thread jmp_buf segv_env; static void segv_handler(int sig, siginfo_t* info, void* ctx) { if (__atomic_load_n(&clone_ongoing, __ATOMIC_RELAXED) != 0) { exit(sig); } uintptr_t addr = (uintptr_t)info->si_addr; const uintptr_t prog_start = 1 << 20; const uintptr_t prog_end = 100 << 20; int skip = __atomic_load_n(&skip_segv, __ATOMIC_RELAXED) != 0; int valid = addr < prog_start || addr > prog_end; if (skip && valid) { _longjmp(segv_env, 1); } exit(sig); } static void install_segv_handler(void) { struct sigaction sa; memset(&sa, 0, sizeof(sa)); sa.sa_handler = SIG_IGN; syscall(SYS_rt_sigaction, 0x20, &sa, NULL, 8); syscall(SYS_rt_sigaction, 0x21, &sa, NULL, 8); memset(&sa, 0, sizeof(sa)); sa.sa_sigaction = segv_handler; sa.sa_flags = SA_NODEFER | SA_SIGINFO; sigaction(SIGSEGV, &sa, NULL); sigaction(SIGBUS, &sa, NULL); } #define NONFAILING(...) \ ({ \ int ok = 1; \ __atomic_fetch_add(&skip_segv, 1, __ATOMIC_SEQ_CST); \ if (_setjmp(segv_env) == 0) { \ __VA_ARGS__; \ } else \ ok = 0; \ __atomic_fetch_sub(&skip_segv, 1, __ATOMIC_SEQ_CST); \ ok; \ }) static void sleep_ms(uint64_t ms) { usleep(ms * 1000); } static uint64_t current_time_ms(void) { struct timespec ts; if (clock_gettime(CLOCK_MONOTONIC, &ts)) exit(1); return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000; } static void use_temporary_dir(void) { char tmpdir_template[] = "./syzkaller.XXXXXX"; char* tmpdir = mkdtemp(tmpdir_template); if (!tmpdir) exit(1); if (chmod(tmpdir, 0777)) exit(1); if (chdir(tmpdir)) exit(1); } 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; } #define FS_IOC_SETFLAGS _IOW('f', 2, long) static void remove_dir(const char* dir) { int iter = 0; DIR* dp = 0; retry: const int umount_flags = MNT_FORCE | UMOUNT_NOFOLLOW; while (umount2(dir, umount_flags) == 0) { } dp = opendir(dir); if (dp == NULL) { if (errno == EMFILE) { exit(1); } exit(1); } struct dirent* ep = 0; while ((ep = readdir(dp))) { if (strcmp(ep->d_name, ".") == 0 || strcmp(ep->d_name, "..") == 0) continue; char filename[FILENAME_MAX]; snprintf(filename, sizeof(filename), "%s/%s", dir, ep->d_name); while (umount2(filename, umount_flags) == 0) { } struct stat st; if (lstat(filename, &st)) exit(1); if (S_ISDIR(st.st_mode)) { remove_dir(filename); continue; } int i; for (i = 0;; i++) { if (unlink(filename) == 0) break; if (errno == EPERM) { int fd = open(filename, O_RDONLY); if (fd != -1) { long flags = 0; if (ioctl(fd, FS_IOC_SETFLAGS, &flags) == 0) { } close(fd); continue; } } if (errno == EROFS) { break; } if (errno != EBUSY || i > 100) exit(1); if (umount2(filename, umount_flags)) exit(1); } } closedir(dp); for (int i = 0;; i++) { if (rmdir(dir) == 0) break; if (i < 100) { if (errno == EPERM) { int fd = open(dir, O_RDONLY); if (fd != -1) { long flags = 0; if (ioctl(fd, FS_IOC_SETFLAGS, &flags) == 0) { } close(fd); continue; } } if (errno == EROFS) { break; } if (errno == EBUSY) { if (umount2(dir, umount_flags)) exit(1); continue; } if (errno == ENOTEMPTY) { if (iter < 100) { iter++; goto retry; } } } exit(1); } } static void kill_and_wait(int pid, int* status) { kill(-pid, SIGKILL); kill(pid, SIGKILL); for (int i = 0; i < 100; i++) { if (waitpid(-1, status, WNOHANG | __WALL) == pid) return; usleep(1000); } DIR* dir = opendir("/sys/fs/fuse/connections"); if (dir) { for (;;) { struct dirent* ent = readdir(dir); if (!ent) break; if (strcmp(ent->d_name, ".") == 0 || strcmp(ent->d_name, "..") == 0) continue; char abort[300]; snprintf(abort, sizeof(abort), "/sys/fs/fuse/connections/%s/abort", ent->d_name); int fd = open(abort, O_WRONLY); if (fd == -1) { continue; } if (write(fd, abort, 1) < 0) { } close(fd); } closedir(dir); } else { } while (waitpid(-1, status, __WALL) != pid) { } } static void setup_test() { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); write_file("/proc/self/oom_score_adj", "1000"); if (symlink("/dev/binderfs", "./binderfs")) { } } static void setup_sysctl() { char mypid[32]; snprintf(mypid, sizeof(mypid), "%d", getpid()); struct { const char* name; const char* data; } files[] = { {"/sys/kernel/debug/x86/nmi_longest_ns", "10000000000"}, {"/proc/sys/kernel/hung_task_check_interval_secs", "20"}, {"/proc/sys/net/core/bpf_jit_kallsyms", "1"}, {"/proc/sys/net/core/bpf_jit_harden", "0"}, {"/proc/sys/kernel/kptr_restrict", "0"}, {"/proc/sys/kernel/softlockup_all_cpu_backtrace", "1"}, {"/proc/sys/fs/mount-max", "100"}, {"/proc/sys/vm/oom_dump_tasks", "0"}, {"/proc/sys/debug/exception-trace", "0"}, {"/proc/sys/kernel/printk", "7 4 1 3"}, {"/proc/sys/kernel/keys/gc_delay", "1"}, {"/proc/sys/vm/oom_kill_allocating_task", "1"}, {"/proc/sys/kernel/ctrl-alt-del", "0"}, {"/proc/sys/kernel/cad_pid", mypid}, }; for (size_t i = 0; i < sizeof(files) / sizeof(files[0]); i++) { if (!write_file(files[i].name, files[i].data)) printf("write to %s failed: %s\n", files[i].name, strerror(errno)); } } static void execute_one(void); #define WAIT_FLAGS __WALL static void loop(void) { int iter = 0; for (;; iter++) { char cwdbuf[32]; sprintf(cwdbuf, "./%d", iter); if (mkdir(cwdbuf, 0777)) exit(1); int pid = fork(); if (pid < 0) exit(1); if (pid == 0) { if (chdir(cwdbuf)) exit(1); setup_test(); execute_one(); exit(0); } int status = 0; uint64_t start = current_time_ms(); for (;;) { if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid) break; sleep_ms(1); if (current_time_ms() - start < 5000) continue; kill_and_wait(pid, &status); break; } remove_dir(cwdbuf); } } uint64_t r[5] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff}; void execute_one(void) { intptr_t res = 0; if (write(1, "executing program\n", sizeof("executing program\n") - 1)) { } NONFAILING(*(uint32_t*)0x20000340 = 2); NONFAILING(*(uint32_t*)0x20000344 = 4); NONFAILING(*(uint32_t*)0x20000348 = 8); NONFAILING(*(uint32_t*)0x2000034c = 1); NONFAILING(*(uint32_t*)0x20000350 = 0x80); NONFAILING(*(uint32_t*)0x20000354 = -1); NONFAILING(*(uint32_t*)0x20000358 = 0); NONFAILING(memset((void*)0x2000035c, 0, 16)); NONFAILING(*(uint32_t*)0x2000036c = 0); NONFAILING(*(uint32_t*)0x20000370 = -1); NONFAILING(*(uint32_t*)0x20000374 = 0); NONFAILING(*(uint32_t*)0x20000378 = 0); NONFAILING(*(uint32_t*)0x2000037c = 0); NONFAILING(*(uint64_t*)0x20000380 = 0); res = syscall(__NR_bpf, /*cmd=*/0ul, /*arg=*/0x20000340ul, /*size=*/0x48ul); if (res != -1) r[0] = res; NONFAILING(*(uint32_t*)0x20000480 = r[0]); syscall(__NR_bpf, /*cmd=*/0x16ul, /*arg=*/0x20000480ul, /*size=*/4ul); NONFAILING(*(uint32_t*)0x200004c0 = 0x11); NONFAILING(*(uint32_t*)0x200004c4 = 0x18); NONFAILING(*(uint64_t*)0x200004c8 = 0x200001c0); NONFAILING( memcpy((void*)0x200001c0, "\x18\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\xb7\x08\x00\x00\x00\x00\x00\x00\x7b\x8a\xf8\xff\x00\x00\x00\x00" "\xb7\x08\x00\x00\x00\x00\x00\x00\x7b\x8a\xf0\xff\x00\x00\x00\x00" "\xbf\xa1\x00\x00\x00\x00\x00\x00\x07\x01\x00\x00\xf8\xff\xff\xff" "\xbf\xa4\x00\x00\x00\x00\x00\x00\x07\x04\x00\x00\xf0\xff\xff\xff" "\xb7\x02\x00\x00\x00\x00\x00\x00\x18\x23\x00\x00", 92)); NONFAILING(*(uint32_t*)0x2000021c = r[0]); NONFAILING(memcpy( (void*)0x20000220, "\x00\x00\x00\x00\x00\x00\x00\x00\xb7\x05\x00\x00\x00\x00\x00\x00\x85\x00" "\x00\x00\xa5\x00\x00\x00\x18\x01\x00\x00\x20\x20\x64\x05\x00\x00\x00\x00" "\x00\x20\x20\x20\x7b\x1a\xf8\xff\x00\x00\x00\x00\xbf\xa1\x00\x00\x00\x00" "\x00\x00\x07\x01\x00\x00\xf8\xff\xff\xff\xb7\x02\x00\x00\x08\x00\x00\x00" "\xb7\x03\x00\x00\x00\x00\x00\x00\xa5\x00\x00\x00\x08\x00\x00\x00\x95", 89)); NONFAILING(*(uint64_t*)0x200004d0 = 0x20000600); NONFAILING(memcpy((void*)0x20000600, "GPL\000", 4)); NONFAILING(*(uint32_t*)0x200004d8 = 0); NONFAILING(*(uint32_t*)0x200004dc = 0); NONFAILING(*(uint64_t*)0x200004e0 = 0); NONFAILING(*(uint32_t*)0x200004e8 = 0); NONFAILING(*(uint32_t*)0x200004ec = 0); NONFAILING(memset((void*)0x200004f0, 0, 16)); NONFAILING(*(uint32_t*)0x20000500 = 0); NONFAILING(*(uint32_t*)0x20000504 = 0); NONFAILING(*(uint32_t*)0x20000508 = 0); NONFAILING(*(uint32_t*)0x2000050c = 0); NONFAILING(*(uint64_t*)0x20000510 = 0); NONFAILING(*(uint32_t*)0x20000518 = 0); NONFAILING(*(uint32_t*)0x2000051c = 0); NONFAILING(*(uint64_t*)0x20000520 = 0); NONFAILING(*(uint32_t*)0x20000528 = 0); NONFAILING(*(uint32_t*)0x2000052c = 0); NONFAILING(*(uint32_t*)0x20000530 = 0); NONFAILING(*(uint32_t*)0x20000534 = 0); NONFAILING(*(uint64_t*)0x20000538 = 0); NONFAILING(*(uint64_t*)0x20000540 = 0); NONFAILING(*(uint32_t*)0x20000548 = 0); NONFAILING(*(uint32_t*)0x2000054c = 0); res = syscall(__NR_bpf, /*cmd=*/5ul, /*arg=*/0x200004c0ul, /*size=*/0x90ul); if (res != -1) r[1] = res; NONFAILING(*(uint64_t*)0x200001c0 = 0x20000000); NONFAILING(memcpy((void*)0x20000000, "kfree\000", 6)); NONFAILING(*(uint32_t*)0x200001c8 = r[1]); syscall(__NR_bpf, /*cmd=*/0x11ul, /*arg=*/0x200001c0ul, /*size=*/0x10ul); NONFAILING(memcpy((void*)0x20000040, "/dev/ppp\000", 9)); res = syscall(__NR_openat, /*fd=*/0xffffffffffffff9cul, /*file=*/0x20000040ul, /*flags=*/0ul, /*mode=*/0ul); if (res != -1) r[2] = res; syscall(__NR_ioctl, /*fd=*/r[2], /*cmd=*/0xc004743e, /*arg=*/0x20001400ul); syscall(__NR_bpf, /*cmd=*/5ul, /*arg=*/0ul, /*size=*/0ul); NONFAILING(*(uint32_t*)0x20000340 = 2); NONFAILING(*(uint32_t*)0x20000344 = 4); NONFAILING(*(uint32_t*)0x20000348 = 8); NONFAILING(*(uint32_t*)0x2000034c = 1); NONFAILING(*(uint32_t*)0x20000350 = 0x80); NONFAILING(*(uint32_t*)0x20000354 = -1); NONFAILING(*(uint32_t*)0x20000358 = 0); NONFAILING(memset((void*)0x2000035c, 0, 16)); NONFAILING(*(uint32_t*)0x2000036c = 0); NONFAILING(*(uint32_t*)0x20000370 = -1); NONFAILING(*(uint32_t*)0x20000374 = 0); NONFAILING(*(uint32_t*)0x20000378 = 0); NONFAILING(*(uint32_t*)0x2000037c = 0); NONFAILING(*(uint64_t*)0x20000380 = 0); res = syscall(__NR_bpf, /*cmd=*/0ul, /*arg=*/0x20000340ul, /*size=*/0x48ul); if (res != -1) r[3] = res; NONFAILING(*(uint32_t*)0x20000480 = r[3]); syscall(__NR_bpf, /*cmd=*/0x16ul, /*arg=*/0x20000480ul, /*size=*/4ul); NONFAILING(*(uint32_t*)0x200004c0 = 0x11); NONFAILING(*(uint32_t*)0x200004c4 = 0x18); NONFAILING(*(uint64_t*)0x200004c8 = 0x200001c0); NONFAILING( memcpy((void*)0x200001c0, "\x18\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\xb7\x08\x00\x00\x00\x00\x00\x00\x7b\x8a\xf8\xff\x00\x00\x00\x00" "\xb7\x08\x00\x00\x00\x00\x00\x00\x7b\x8a\xf0\xff\x00\x00\x00\x00" "\xbf\xa1\x00\x00\x00\x00\x00\x00\x07\x01\x00\x00\xf8\xff\xff\xff" "\xbf\xa4\x00\x00\x00\x00\x00\x00\x07\x04\x00\x00\xf0\xff\xff\xff" "\xb7\x02\x00\x00\x00\x00\x00\x00\x18\x23\x00\x00", 92)); NONFAILING(*(uint32_t*)0x2000021c = r[3]); NONFAILING(memcpy( (void*)0x20000220, "\x00\x00\x00\x00\x00\x00\x00\x00\xb7\x05\x00\x00\x10\x00\x00\x00\x85\x00" "\x00\x00\xa5\x00\x00\x00\x18\x01\x00\x00\x20\x20\x64\x05\x00\x00\x00\x00" "\x00\x20\x20\x20\x7b\x1a\xf8\xff\x00\x00\x00\x00\xbf\xa1\x00\x00\x00\x00" "\x00\x00\x07\x01\x00\x00\xf8\xff\xff\xff\xb7\x02\x00\x00\x08\x00\x00\x00" "\xb7\x03\x00\x00\x00\x00\x00\x00\xa5\x00\x00\x00\x08\x00\x00\x00\x95", 89)); NONFAILING(*(uint64_t*)0x200004d0 = 0x20000600); NONFAILING(memcpy((void*)0x20000600, "GPL\000", 4)); NONFAILING(*(uint32_t*)0x200004d8 = 0); NONFAILING(*(uint32_t*)0x200004dc = 0); NONFAILING(*(uint64_t*)0x200004e0 = 0); NONFAILING(*(uint32_t*)0x200004e8 = 0); NONFAILING(*(uint32_t*)0x200004ec = 0); NONFAILING(memset((void*)0x200004f0, 0, 16)); NONFAILING(*(uint32_t*)0x20000500 = 0); NONFAILING(*(uint32_t*)0x20000504 = 0); NONFAILING(*(uint32_t*)0x20000508 = 0); NONFAILING(*(uint32_t*)0x2000050c = 0); NONFAILING(*(uint64_t*)0x20000510 = 0); NONFAILING(*(uint32_t*)0x20000518 = 0); NONFAILING(*(uint32_t*)0x2000051c = 0); NONFAILING(*(uint64_t*)0x20000520 = 0); NONFAILING(*(uint32_t*)0x20000528 = 0); NONFAILING(*(uint32_t*)0x2000052c = 0); NONFAILING(*(uint32_t*)0x20000530 = 0); NONFAILING(*(uint32_t*)0x20000534 = 0); NONFAILING(*(uint64_t*)0x20000538 = 0); NONFAILING(*(uint64_t*)0x20000540 = 0); NONFAILING(*(uint32_t*)0x20000548 = 0); NONFAILING(*(uint32_t*)0x2000054c = 0); res = syscall(__NR_bpf, /*cmd=*/5ul, /*arg=*/0x200004c0ul, /*size=*/0x90ul); if (res != -1) r[4] = res; NONFAILING(*(uint64_t*)0x200001c0 = 0x20000000); NONFAILING(memcpy((void*)0x20000000, "kfree\000", 6)); NONFAILING(*(uint32_t*)0x200001c8 = r[4]); syscall(__NR_bpf, /*cmd=*/0x11ul, /*arg=*/0x200001c0ul, /*size=*/0x10ul); } int main(void) { syscall(__NR_mmap, /*addr=*/0x1ffff000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x20000000ul, /*len=*/0x1000000ul, /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/ 7ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x21000000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1, /*offset=*/0ul); setup_sysctl(); install_segv_handler(); for (procid = 0; procid < 5; procid++) { if (fork() == 0) { use_temporary_dir(); loop(); } } sleep(1000000); return 0; }