// https://syzkaller.appspot.com/bug?id=5bbec74cb4d7b4ae0ac1e45d4a965fdaa3413422 // 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*)0x20000040 = 0x21; *(uint16_t*)0x20000042 = 0; *(uint16_t*)0x20000044 = 2; *(uint16_t*)0x20000046 = 0x10; *(uint16_t*)0x20000048 = 2; *(uint16_t*)0x2000004a = htobe16(0); *(uint32_t*)0x2000004c = htobe32(0x7f000001); syscall(__NR_connect, r[0], 0x20000040ul, 0x24ul); *(uint64_t*)0x20005c00 = 0; *(uint32_t*)0x20005c08 = 0; *(uint64_t*)0x20005c10 = 0; *(uint64_t*)0x20005c18 = 0; *(uint64_t*)0x20005c20 = 0x20000200; memcpy((void*)0x20000200, "\x18\x00\x00\x00\x00\x00\x00\x00\x10\x01\x00\x00\x01\x00\x00\x00\x77" "\x00\x00\xf2\x00\x00\x00\x00\xa6\xe2\x17\xb9\x1c\x3b\x0d\x87\x37\x22" "\xb4\x1a\x11\x8f\xd5\x8a\xa1\xf0\xa3\x9a\xd9\x58\x22\x03\xda\xa3\x2c" "\x98\x31\x69\x9a\xcc\x52\xf1\x41\xee\xca\x2b\xd1\x2d\x2f\x6f\xb5\x4e" "\x5b\xff\x40\xe0\x62\xa4\x3f\x80\xb1\xba\xbf\xd0\x76\xd2\x50\x28\x92" "\x25\x0d\xee\xe2\x72\x83\x16\xe6\x3e\x58\x9d\xdf\x14\x2e\x89\x36\x5b" "\xd4\x8c\xf7\x66\x02\xc6\xf6\xaa\x76\xbc\x37\x28\x47\x32\xbd\x1e\x19" "\x1d\xdd\x3c\x9f\x31\x0f\x82\x7c\x19\x5f\x3c\x49\x57\xc6\x7a\x08\x46" "\x65\x17\xba\x13\x6c\x8c\x9e\x01\x00\x00\x00\xf8\xff\xff\xff\xff\xff" "\xff\xff\x3e\x26\xb5\xca\x26\xbb\x43\x4d\xbd\x0e\x50\x85\xc2\x94\xe5" "\x77\xbb\x08\x18\x76\xe6\x3e\x7c\x28\x34\x53\x39\x25\xdb\x8b\x54\xb3" "\x3d\xa7\xb9\x47\xa6\xfc\xa1\xf9\xc4\x9c\x64\x8d\x58\xd4\xf9\x44\x26" "\x4f\xca\xce\x71\xd5\xc7\x98\xcd\x3c\x13\xd7\x08\x3a\x7e\xb4\xc5\x26" "\xe0\x72\xa2\x3b\xd2\x4c\xcc\xb3\x8e\x4e\xff\x54\x25\x20\x85\x8c\x94" "\x0f\xbb\x95\x97\x9a\x56\x4d\x73\xa7\xaf\x10\x7f\xd5\xdd\xaa\x49\x18" "\x38\x87\x39\x14\xa4\x67\xc3\xce\x28\x05\x68\x33\xeb\x45\x59\x86\x43" "\x17\xc0\xa1\xda\xc9\x2d\x09\x0f\x4f\x90\x93\x67\x97\x91\xa2\x84\x0f" "\x28\x51\x32\x4a\xcd\xf4\x4a\x80\x7e\x69\xa1\xbc\x25\xd2\x65\x30\x30" "\x04\xe8\xea\xd1\x28\xa3\xd6\x1c\x00\x63\x23\x35\x01\xcf\xdf\x76\xd9" "\x9d\xbc\x46\xb9\xc0\x02\x03\xa9\x16\x1b\x8a\x44\x40\x01\xc3\x86\x47" "\x5c\x43\x2c\x7a\x6e\x89\x88\x85\x42\x90\x63\x95\x4e\xa0\xbd\x2f\x34" "\x85\xd9\x9a\xb3\x8a\x32\x31\xea\x08\x58\x47\x95\x64\x7d\xdb\x75\xc5" "\x93\x93\x3e\x82\x4a\xcd\xab\x29\x24\x82\x73\x5c\xd9\x15\x72\xd0\xbc" "\x3f\x95\xb6\x1e\x03\x91\x83\xf5\xed\x7c\xb7\x5f\x2b\xa7\x92\x96\xf7" "\x3c\xa6\xf0\x0a\x0f\x6c\xe5\xc2\xbc\x03\x95\x7a\x77\xdb\xd2\x29\x92" "\x11\x24\x58\x0f\xc4\xdd\xd4\xaa\x3f\x37\x52\xc7\xf2\xdc\xa3\xda\x2b" "\xa7\xb7\x72\xe0\x12\x15\xf0\x5d\xc1\xcf\x74\xdd\xf5\x1a\xf1\xa4\xeb" "\xba\x44\x33\x74\xe0\x9d\x5f\xf9\x6d\xb1\xa1\xa6\x03\x68\x49\x3f\xf3" "\x00\x00\x00\x00\xd3\x49\x16\x16\x94\x26\x3e\x68\xdb\xce\xe9\xb1\xc7" "\xb0\x45\x4a\x7c\x11\x75\xf6\xb2\x70\x1b\xcf\x6a\xed\xf5\xe9\xed\xa6" "\x90\xbd\x39\x1c\x8b\xa2\x67\x82\xce\xea\x5b\x17\x73\x9a\xb7\x49\xf0" "\x26\xed\xa3\x54\x48\x09\xe7\x80\x62\x94\xa3\x74\x05\xb1\xeb\xab\x39", 544); *(uint64_t*)0x20005c28 = 0x18; *(uint32_t*)0x20005c30 = 0; *(uint32_t*)0x20005c38 = 0; syscall(__NR_sendmmsg, r[0], 0x20005c00ul, 1ul, 0x4048000ul); close_fds(); } int main(void) { syscall(__NR_mmap, 0x20000000ul, 0x1000000ul, 3ul, 0x32ul, -1, 0); do_sandbox_none(); return 0; }