// https://syzkaller.appspot.com/bug?id=d24737e004c679ad45678f20e9aec57c98f9b478 // 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 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; } #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)) { } if (symlink("/dev/binderfs", "./binderfs")) { } } 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 = 0; 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)) { } setup_binderfs(); loop(); 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"); } 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++) { int pid = fork(); if (pid < 0) exit(1); if (pid == 0) { 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; } } } uint64_t r[4] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff, 0x0}; void execute_one(void) { intptr_t res = 0; res = syscall(__NR_socket, 0xaul, 2ul, 0); if (res != -1) r[0] = res; res = syscall(__NR_socket, 0x10ul, 3ul, 0); if (res != -1) r[1] = res; res = syscall(__NR_socket, 0x10ul, 0x803ul, 0); if (res != -1) r[2] = res; *(uint64_t*)0x20000380 = 0; *(uint32_t*)0x20000388 = 0; *(uint64_t*)0x20000390 = 0x20000340; *(uint64_t*)0x20000340 = 0; *(uint64_t*)0x20000348 = 0x14; *(uint64_t*)0x20000398 = 1; *(uint64_t*)0x200003a0 = 0; *(uint64_t*)0x200003a8 = 0; *(uint32_t*)0x200003b0 = 0; syscall(__NR_sendmsg, r[2], 0x20000380ul, 0ul); *(uint32_t*)0x200000c0 = 0x14; res = syscall(__NR_getsockname, r[2], 0x20000100ul, 0x200000c0ul); if (res != -1) r[3] = *(uint32_t*)0x20000104; *(uint64_t*)0x20000080 = 0; *(uint32_t*)0x20000088 = 0; *(uint64_t*)0x20000090 = 0x20000500; *(uint64_t*)0x20000500 = 0x20000180; *(uint32_t*)0x20000180 = 0x60; *(uint16_t*)0x20000184 = 0x10; *(uint16_t*)0x20000186 = 0x439; *(uint32_t*)0x20000188 = 0; *(uint32_t*)0x2000018c = 0; *(uint8_t*)0x20000190 = 0; *(uint8_t*)0x20000191 = 0; *(uint16_t*)0x20000192 = 0; *(uint32_t*)0x20000194 = 0; *(uint32_t*)0x20000198 = 0x9801; *(uint32_t*)0x2000019c = 0; *(uint16_t*)0x200001a0 = 0x40; STORE_BY_BITMASK(uint16_t, , 0x200001a2, 0x12, 0, 14); STORE_BY_BITMASK(uint16_t, , 0x200001a3, 0, 6, 1); STORE_BY_BITMASK(uint16_t, , 0x200001a3, 1, 7, 1); *(uint16_t*)0x200001a4 = 8; *(uint16_t*)0x200001a6 = 1; memcpy((void*)0x200001a8, "sit\000", 4); *(uint16_t*)0x200001ac = 0x34; STORE_BY_BITMASK(uint16_t, , 0x200001ae, 2, 0, 14); STORE_BY_BITMASK(uint16_t, , 0x200001af, 0, 6, 1); STORE_BY_BITMASK(uint16_t, , 0x200001af, 1, 7, 1); *(uint16_t*)0x200001b0 = 8; *(uint16_t*)0x200001b2 = 1; *(uint32_t*)0x200001b4 = r[3]; *(uint16_t*)0x200001b8 = 6; *(uint16_t*)0x200001ba = 0xf; *(uint16_t*)0x200001bc = 2; *(uint16_t*)0x200001c0 = 6; *(uint16_t*)0x200001c2 = 0x11; *(uint16_t*)0x200001c4 = htobe16(0x4e21); *(uint16_t*)0x200001c8 = 6; *(uint16_t*)0x200001ca = 0x11; *(uint16_t*)0x200001cc = htobe16(0x4e24); *(uint16_t*)0x200001d0 = 8; *(uint16_t*)0x200001d2 = 2; *(uint8_t*)0x200001d4 = 0xac; *(uint8_t*)0x200001d5 = 0x14; *(uint8_t*)0x200001d6 = 0x14; *(uint8_t*)0x200001d7 = 0x16; *(uint16_t*)0x200001d8 = 6; *(uint16_t*)0x200001da = 0x10; *(uint16_t*)0x200001dc = 0xfff; *(uint64_t*)0x20000508 = 0x60; *(uint64_t*)0x20000098 = 1; *(uint64_t*)0x200000a0 = 0; *(uint64_t*)0x200000a8 = 0; *(uint32_t*)0x200000b0 = 0; syscall(__NR_sendmsg, r[1], 0x20000080ul, 0x20048894ul); *(uint64_t*)0x200017c0 = 0x20000040; *(uint16_t*)0x20000040 = 2; *(uint16_t*)0x20000042 = htobe16(0x4e20); *(uint32_t*)0x20000044 = htobe32(0xe0000001); *(uint32_t*)0x200017c8 = 0x10; *(uint64_t*)0x200017d0 = 0; *(uint64_t*)0x200017d8 = 0; *(uint64_t*)0x200017e0 = 0x20000000; *(uint64_t*)0x20000000 = 0x1c; *(uint32_t*)0x20000008 = 0; *(uint32_t*)0x2000000c = 8; *(uint32_t*)0x20000010 = r[3]; *(uint32_t*)0x20000014 = htobe32(0); *(uint8_t*)0x20000018 = 0xac; *(uint8_t*)0x20000019 = 0x14; *(uint8_t*)0x2000001a = 0x14; *(uint8_t*)0x2000001b = 0xbb; *(uint64_t*)0x200017e8 = 0x20; *(uint32_t*)0x200017f0 = 0; *(uint32_t*)0x200017f8 = 0; syscall(__NR_sendmmsg, r[0], 0x200017c0ul, 1ul, 0ul); } 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); do_sandbox_none(); return 0; }