// https://syzkaller.appspot.com/bug?id=0ff29101efe3523c886bd8b912945241a1c6b1b4 // 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 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 loop(); static void sandbox_common() { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); 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 (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); } 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)) { } loop(); exit(1); } static void close_fds() { int fd; for (fd = 3; fd < MAX_FDS; fd++) close(fd); } uint64_t r[1] = {0xffffffffffffffff}; void loop(void) { intptr_t res = 0; res = syscall(__NR_socket, 0x2000000000000021ul, 2ul, 2); if (res != -1) r[0] = res; *(uint16_t*)0x20000080 = 0x21; *(uint16_t*)0x20000082 = 0; *(uint16_t*)0x20000084 = 2; *(uint16_t*)0x20000086 = 0x10; *(uint16_t*)0x20000088 = 2; *(uint16_t*)0x2000008a = htobe16(0x4e24); *(uint8_t*)0x2000008c = 0xac; *(uint8_t*)0x2000008d = 0x14; *(uint8_t*)0x2000008e = 0x14; *(uint8_t*)0x2000008f = 0x1e; syscall(__NR_connect, r[0], 0x20000080ul, 0x24ul); *(uint64_t*)0x20005c00 = 0; *(uint32_t*)0x20005c08 = 0; *(uint64_t*)0x20005c10 = 0; *(uint64_t*)0x20005c18 = 0; *(uint64_t*)0x20005c20 = 0x20000600; memcpy( (void*)0x20000600, "\x18\x00\x00\x00\x00\x00\x00\x00\x10\x01\x00\x00\x01\x00\x00\x00\x77\x00" "\x46\xd9\x00\x00\x00\x00\x00\x00\xf4\x1b\x25\xe4\x06\xd5\x89\x37\xe7\xe8" "\x99\xe0\x52\x48\x2f\xc9\x57\x7f\x89\xf7\x1e\xbd\xdf\x07\x77\x98\xc1\xfb" "\x74\xed\x80\x23\xd1\x96\x26\x07\x4d\x27\xee\x6f\x22\x10\xb4\x7a\xb4\xa7" "\x69\x07\x47\x7a\x20\x95\x22\xad\xca\x7e\x54\xff\xb7\xde\xc9\xd9\xa6\xd8" "\x27\x3a\xcf\x83\x71\xac\x36\x19\x73\x05\xc0\x4a\x8c\xcf\xfc\xa5\x6c\xcb" "\xca\xbf\xb2\x5c\xc9\x46\x28\x34\x8a\x24\x59\x3c\x5d\xbd\xf2\x00\x79\x6a" "\x8f\xd2\x17\x36\x7c\x01\x7f\x76\xf1\x31\xc8\x69\x3a\xc4\x3b\x77\x47\x1b" "\xf2\x02\x60\xc6\x81\x33\xc3\x3f\x37\x5d\x17\x35\x0e\xe9\x14\x70\x7d\x2c" "\x35\x45\xb8\x12\xf7\xf5\x8f\x43\x67\x06\xf1\x7b\x26\xae\xba\xc8\xe1\xae" "\x91\x33\x79\x90\x24\x36\x61\x0c\x52\xb7\x24\x99\x31\x41\xa5\xcb\x7a\x0a" "\x9c\x3d\xca\x0a\x16\x78\x7a\x4d\x0c\x82\xe2\xd9\x82\x92\x19\xe3\xd9\x81" "\xd1\x96\xf1\xb7\x25\x6c\x49\xaa\xcd\x6b\x00\x00\x00\x00\x21\x50\xa4\x05" "\x8a\x8e\x43\x47\xe1\x3f\x94\xbe\x6d\x87\xfc\x7e\xcd\xaf\xb8\x8b\x1a\x5c" "\x00\x17\xa5\x35\x52\xe6\x79\x7c\x05\x61\x03\xb8\xd9\xe4\xea\xc3\xf0\x07" "\x65\x11\x65\x73\xf3\x80\xf6\xe7\x6a\xec\x10\x1f\xc9\x35\xc5\xc2\x5f\xac" "\xa1\x07\x1a\x96\xf3\xd5\xfd\xf7\xa8\xe7\xb9\x07\xd2\x36\xe9\x1a\x44\x92" "\xa2\x6a\x99\x4d\x04\xe3\xef\xed\x34\x9e\x81\xbc\x3b\x01\xcc\x53\x17\x78" "\x25\xfd\x34\x4c\x96\x8b\x8e\xaa\x41\xda\xa0\x14\x51\x1d\x5d\x1c\x05\x8a" "\x87\xe0\x01\xa4\xd1\xd6\xd4\x9d\xda\xba\x8c\x94\xe8\xc3\x9d\x69\x3d\x40" "\x1f\xa1\xcf\x52\x6e\xa5\x7d\x4d\x80\x66\x47\x5f\x49\x11\x0e\x67\x8c\x7e" "\xec\x10\xe2\x25\xe2\x34\x79\x89\xaf\x46\xcf\x48\x49\xc7\xab\x66\x64\x93" "\xd4\xd2\xc8\xc1\xe5\xf3\xc9\x7b\x06\x9e\x48\xfe\x79\x69\x86\xd2\x42\x90" "\x4f\x33\xe2\x84\xf6\x42\xbb\x7d\x14\x8c\x63\x4b\x77\xe3\x9b\x19\xea\xe2" "\xc2\x83\x1d\xad\xf0\xe6\x6a\x78\xf5\xdb\x7b\x39\x77\xb6\x08\xcc\xfd\x60" "\xa4\x27\x66\x85\x99\x79\x90\x23\xec\x7c\x56\x7e\x0b\xf7\xcd\x0d\x3a\xb4" "\x50\x0f\x0d\x0f\xcd\x95\x3d\xe8\xa7\x4a\xbe\x77\x15\x0f\x9b\x0f\xcf\x34" "\x72\xd1\x45\x1b\x09\x14\xf4\xa7\xb0\x04\xc5\x56\x2b\x9d\xc6\xd3\x7e\xd3" "\x12\x8e\xc4\xac\x4f\x2e\x3b\x58\x23\x80\x77\xb0\xbd\xe8\x74\xcc\xaf\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xf3\xbf\x49\x7c" "\xba\xa2\xc0\xa1\x1f\x8b\x36\x30\xa0\x49\x7d\x98\xa0\xc7\x81\x36\x02\x61" "\xa8\x6c\x82\xe9\xca\xce\xc3\xfd\xdc\xb7\x7a\x77\xcd\x56\x75\xf5\xa8\xbf" "\xdd\x7c\xab\x5a\xbb\xbf\x61\xe5\x99\x90\x18\x06\x7c\xa4\x7d\x64\x12\xbf" "\x62\xcb\x5a\xca\xbd\x40\x82\x17\xbd\xb4\xc0\xa5\xe3\x87\x9b\xc4\xa6\xf0" "\xf6\xe4\xe2\x48\xef\x86\xa0\xed\x82\x4f\x38\xe7\xaf\xf9\xf2\x70\xb1\x86" "\x82\xaa\xe1\x49\x06\x68\xb0\xae\x15\xb9\x6d\x89\x32\x2f\xdd\x0f\xd3\xbe" "\x38\x35\x47\x13\x2f", 653); *(uint64_t*)0x20005c28 = 0x18; *(uint32_t*)0x20005c30 = 0; *(uint32_t*)0x20005c38 = 0; syscall(__NR_sendmmsg, r[0], 0x20005c00ul, 1ul, 0ul); close_fds(); } int main(void) { syscall(__NR_mmap, 0x20000000ul, 0x1000000ul, 3ul, 0x32ul, -1, 0); do_sandbox_none(); return 0; }