// https://syzkaller.appspot.com/bug?id=895ad4d2f53bb935db4fcbc03e66436a8a5082d3 // 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 #include #include #include static unsigned long long procid; 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); } #define BITMASK(bf_off, bf_len) (((1ull << (bf_len)) - 1) << (bf_off)) #define STORE_BY_BITMASK(type, htobe, addr, val, bf_off, bf_len) \ *(type*)(addr) = \ htobe((htobe(*(type*)(addr)) & ~BITMASK((bf_off), (bf_len))) | \ (((type)(val) << (bf_off)) & BITMASK((bf_off), (bf_len)))) 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 MAX_FDS 30 static void setup_common() { if (mount(0, "/sys/fs/fuse/connections", "fusectl", 0, 0)) { } } static void setup_binderfs() { if (mkdir("/dev/binderfs", 0777)) { } if (mount("binder", "/dev/binderfs", "binder", 0, NULL)) { } } static void loop(); static void sandbox_common() { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setsid(); struct rlimit rlim; rlim.rlim_cur = rlim.rlim_max = (200 << 20); setrlimit(RLIMIT_AS, &rlim); rlim.rlim_cur = rlim.rlim_max = 32 << 20; setrlimit(RLIMIT_MEMLOCK, &rlim); rlim.rlim_cur = rlim.rlim_max = 136 << 20; setrlimit(RLIMIT_FSIZE, &rlim); rlim.rlim_cur = rlim.rlim_max = 1 << 20; setrlimit(RLIMIT_STACK, &rlim); rlim.rlim_cur = rlim.rlim_max = 128 << 20; setrlimit(RLIMIT_CORE, &rlim); rlim.rlim_cur = rlim.rlim_max = 256; setrlimit(RLIMIT_NOFILE, &rlim); if (unshare(CLONE_NEWNS)) { } if (mount(NULL, "/", NULL, MS_REC | MS_PRIVATE, NULL)) { } if (unshare(CLONE_NEWIPC)) { } if (unshare(0x02000000)) { } if (unshare(CLONE_NEWUTS)) { } if (unshare(CLONE_SYSVSEM)) { } typedef struct { const char* name; const char* value; } sysctl_t; static const sysctl_t sysctls[] = { {"/proc/sys/kernel/shmmax", "16777216"}, {"/proc/sys/kernel/shmall", "536870912"}, {"/proc/sys/kernel/shmmni", "1024"}, {"/proc/sys/kernel/msgmax", "8192"}, {"/proc/sys/kernel/msgmni", "1024"}, {"/proc/sys/kernel/msgmnb", "1024"}, {"/proc/sys/kernel/sem", "1024 1048576 500 1024"}, }; unsigned i; for (i = 0; i < sizeof(sysctls) / sizeof(sysctls[0]); i++) write_file(sysctls[i].name, sysctls[i].value); } static int wait_for_loop(int pid) { if (pid < 0) exit(1); int status = 0; while (waitpid(-1, &status, __WALL) != pid) { } return WEXITSTATUS(status); } static void drop_caps(void) { struct __user_cap_header_struct cap_hdr = {}; struct __user_cap_data_struct cap_data[2] = {}; cap_hdr.version = _LINUX_CAPABILITY_VERSION_3; cap_hdr.pid = getpid(); if (syscall(SYS_capget, &cap_hdr, &cap_data)) exit(1); const int drop = (1 << CAP_SYS_PTRACE) | (1 << CAP_SYS_NICE); cap_data[0].effective &= ~drop; cap_data[0].permitted &= ~drop; cap_data[0].inheritable &= ~drop; if (syscall(SYS_capset, &cap_hdr, &cap_data)) exit(1); } static int do_sandbox_none(void) { if (unshare(CLONE_NEWPID)) { } int pid = fork(); if (pid != 0) return wait_for_loop(pid); setup_common(); sandbox_common(); drop_caps(); if (unshare(CLONE_NEWNET)) { } write_file("/proc/sys/net/ipv4/ping_group_range", "0 65535"); setup_binderfs(); loop(); exit(1); } #define FS_IOC_SETFLAGS _IOW('f', 2, long) static void remove_dir(const char* dir) { int iter = 0; DIR* dp = 0; retry: while (umount2(dir, MNT_DETACH | UMOUNT_NOFOLLOW) == 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, MNT_DETACH | UMOUNT_NOFOLLOW) == 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, MNT_DETACH | UMOUNT_NOFOLLOW)) 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, MNT_DETACH | UMOUNT_NOFOLLOW)) 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 close_fds() { for (int fd = 3; fd < MAX_FDS; fd++) close(fd); } 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(); close_fds(); 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[2] = {0xffffffffffffffff, 0xffffffffffffffff}; void execute_one(void) { intptr_t res = 0; res = syscall(__NR_socket, 0x10ul, 3ul, 0); if (res != -1) r[0] = res; *(uint64_t*)0x20000300 = 0; *(uint32_t*)0x20000308 = 0; *(uint64_t*)0x20000310 = 0x200002c0; *(uint64_t*)0x200002c0 = 0x200000c0; *(uint32_t*)0x200000c0 = 0xcc; *(uint16_t*)0x200000c4 = 0x30; *(uint16_t*)0x200000c6 = -1; *(uint32_t*)0x200000c8 = 0; *(uint32_t*)0x200000cc = 0; *(uint8_t*)0x200000d0 = 0; *(uint8_t*)0x200000d1 = 0; *(uint16_t*)0x200000d2 = 0; *(uint16_t*)0x200000d4 = 0xb8; *(uint16_t*)0x200000d6 = 1; *(uint16_t*)0x200000d8 = 0x6c; STORE_BY_BITMASK(uint16_t, , 0x200000da, 1, 0, 14); STORE_BY_BITMASK(uint16_t, , 0x200000db, 0, 6, 1); STORE_BY_BITMASK(uint16_t, , 0x200000db, 0, 7, 1); *(uint16_t*)0x200000dc = 0xb; *(uint16_t*)0x200000de = 1; memcpy((void*)0x200000e0, "police\000", 7); *(uint16_t*)0x200000e8 = 0x40; STORE_BY_BITMASK(uint16_t, , 0x200000ea, 2, 0, 14); STORE_BY_BITMASK(uint16_t, , 0x200000eb, 0, 6, 1); STORE_BY_BITMASK(uint16_t, , 0x200000eb, 1, 7, 1); *(uint16_t*)0x200000ec = 0x3c; *(uint16_t*)0x200000ee = 1; *(uint32_t*)0x200000f0 = 0; *(uint32_t*)0x200000f4 = 0; *(uint32_t*)0x200000f8 = 0; *(uint32_t*)0x200000fc = 0; *(uint32_t*)0x20000100 = 0; *(uint8_t*)0x20000104 = 0; *(uint8_t*)0x20000105 = 0; *(uint16_t*)0x20000106 = 0; *(uint16_t*)0x20000108 = 0; *(uint16_t*)0x2000010a = 0; *(uint32_t*)0x2000010c = 0; *(uint8_t*)0x20000110 = 0; *(uint8_t*)0x20000111 = 0; *(uint16_t*)0x20000112 = 6; *(uint16_t*)0x20000114 = 0; *(uint16_t*)0x20000116 = 0; *(uint32_t*)0x20000118 = 0; *(uint32_t*)0x2000011c = 0; *(uint32_t*)0x20000120 = 0; *(uint32_t*)0x20000124 = 0; *(uint16_t*)0x20000128 = 4; *(uint16_t*)0x2000012a = 6; *(uint16_t*)0x2000012c = 0xc; *(uint16_t*)0x2000012e = 7; *(uint32_t*)0x20000130 = 0; *(uint32_t*)0x20000134 = 0; *(uint16_t*)0x20000138 = 0xc; *(uint16_t*)0x2000013a = 8; *(uint32_t*)0x2000013c = 0; *(uint32_t*)0x20000140 = 1; *(uint16_t*)0x20000144 = 0x48; STORE_BY_BITMASK(uint16_t, , 0x20000146, 2, 0, 14); STORE_BY_BITMASK(uint16_t, , 0x20000147, 0, 6, 1); STORE_BY_BITMASK(uint16_t, , 0x20000147, 0, 7, 1); *(uint16_t*)0x20000148 = 9; *(uint16_t*)0x2000014a = 1; memcpy((void*)0x2000014c, "gact\000", 5); *(uint16_t*)0x20000154 = 0x1c; STORE_BY_BITMASK(uint16_t, , 0x20000156, 2, 0, 14); STORE_BY_BITMASK(uint16_t, , 0x20000157, 0, 6, 1); STORE_BY_BITMASK(uint16_t, , 0x20000157, 1, 7, 1); *(uint16_t*)0x20000158 = 0x18; *(uint16_t*)0x2000015a = 2; *(uint32_t*)0x2000015c = 0; *(uint32_t*)0x20000160 = 0; *(uint32_t*)0x20000164 = 0x404af8f8; *(uint32_t*)0x20000168 = 0; *(uint32_t*)0x2000016c = 0; *(uint16_t*)0x20000170 = 4; *(uint16_t*)0x20000172 = 6; *(uint16_t*)0x20000174 = 0xc; *(uint16_t*)0x20000176 = 7; *(uint32_t*)0x20000178 = 0; *(uint32_t*)0x2000017c = 0; *(uint16_t*)0x20000180 = 0xc; *(uint16_t*)0x20000182 = 8; *(uint32_t*)0x20000184 = 0; *(uint32_t*)0x20000188 = 0; *(uint64_t*)0x200002c8 = 0xcc; *(uint64_t*)0x20000318 = 1; *(uint64_t*)0x20000320 = 0; *(uint64_t*)0x20000328 = 0; *(uint32_t*)0x20000330 = 0; syscall(__NR_sendmsg, r[0], 0x20000300ul, 0ul); syscall(__NR_rmdir, 0ul); memcpy((void*)0x20000440, "./file0\000", 8); res = syscall(__NR_creat, 0x20000440ul, 0x120ul); if (res != -1) r[1] = res; syscall(__NR_fallocate, r[1], 0x100000011ul, 0ul, 0x2811fdfful); } int main(void) { syscall(__NR_mmap, 0x1ffff000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul); syscall(__NR_mmap, 0x20000000ul, 0x1000000ul, 7ul, 0x32ul, -1, 0ul); syscall(__NR_mmap, 0x21000000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul); for (procid = 0; procid < 6; procid++) { if (fork() == 0) { use_temporary_dir(); do_sandbox_none(); } } sleep(1000000); return 0; }