// https://syzkaller.appspot.com/bug?id=16b2ebdc9899528d52c7aaebac35574a1f87710c // 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; } 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); } uint64_t r[4] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff}; void loop(void) { intptr_t res = 0; res = syscall(__NR_socket, 0x10, 3, 0); if (res != -1) r[0] = res; res = syscall(__NR_socket, 0x10, 3, 0); if (res != -1) r[1] = res; res = syscall(__NR_socket, 0x10, 0x803, 0); if (res != -1) r[2] = res; *(uint64_t*)0x200001c0 = 0; *(uint32_t*)0x200001c8 = 0; *(uint64_t*)0x200001d0 = 0x20000180; *(uint64_t*)0x20000180 = 0; *(uint64_t*)0x20000188 = 0; *(uint64_t*)0x200001d8 = 1; *(uint64_t*)0x200001e0 = 0; *(uint64_t*)0x200001e8 = 0; *(uint32_t*)0x200001f0 = 0; syscall(__NR_sendmsg, r[2], 0x200001c0, 0); *(uint32_t*)0x20000200 = 0xa; res = syscall(__NR_getsockname, r[2], 0x20000100, 0x20000200); if (res != -1) r[3] = *(uint32_t*)0x20000104; *(uint64_t*)0x20000240 = 0; *(uint32_t*)0x20000248 = 0; *(uint64_t*)0x20000250 = 0x20000080; *(uint64_t*)0x20000080 = 0x20000540; *(uint32_t*)0x20000540 = 0x148; *(uint16_t*)0x20000544 = 0x24; *(uint16_t*)0x20000546 = 0x507; *(uint32_t*)0x20000548 = 0; *(uint32_t*)0x2000054c = 0; *(uint8_t*)0x20000550 = 0; *(uint32_t*)0x20000554 = r[3]; *(uint16_t*)0x20000558 = 0; *(uint16_t*)0x2000055a = 0; *(uint16_t*)0x2000055c = -1; *(uint16_t*)0x2000055e = -1; *(uint16_t*)0x20000560 = 0; *(uint16_t*)0x20000562 = 0; *(uint16_t*)0x20000564 = 8; *(uint16_t*)0x20000566 = 1; memcpy((void*)0x20000568, "red\000", 4); *(uint16_t*)0x2000056c = 0x11c; *(uint16_t*)0x2000056e = 2; *(uint16_t*)0x20000570 = 0x104; *(uint16_t*)0x20000572 = 2; memcpy((void*)0x20000574, "\x7c\xba\xf4\xa5\x8f\x3a\x09\xe8\x5c\x09\x77\x3c\x86\x54\x9f\x79\x33" "\x96\x7d\x31\x70\xab\xd4\x7c\x81\xcc\x22\x12\xa8\xde\xa1\x8c\xa1\xf8" "\x13\xbe\x47\x68\x02\xb1\xf3\x8c\x18\x2a\x6e\x7e\xde\x33\x05\x54\x64" "\xcc\xa6\xfa\x40\x8a\xef\x9e\x0f\x31\xb4\xe9\xa7\x70\x82\x70\x2e\x46" "\xbc\xd4\xa0\x18\x7f\x6f\x08\x6f\x7e\xe0\x2a\xaf\x1c\x88\x35\x56\xe0" "\x1c\xde\xba\xf6\x66\x9a\x47\x05\xf8\x03\x92\x58\x5e\x6a\xa8\x45\xd0" "\xc0\xba\x11\xe4\xf6\xef\x81\x09\xb4\xd9\x35\x9e\x98\x34\x88\x1f\x99" "\xe6\xf3\x86\xeb\xcd\x23\xc0\xf4\x70\x40\x72\xb9\x7a\x67\x9c\xdd\x8d" "\x62\x1f\x36\xd7\x28\x2d\xf7\x6c\x0f\x03\xbe\x45\x7d\x49\xca\xe4\xe0" "\x23\x96\x95\x2b\xe7\x6c\xfc\x2a\xda\x7a\x67\x5c\x82\x03\x65\x5a\x55" "\xc5\xbe\x68\x47\xbe\x85\x03\xfe\x70\x1d\xae\x45\xd6\x0e\x62\x36\xf3" "\x24\xee\x47\x16\x18\xbc\x9d\x07\xf9\xcd\x3f\x47\x6e\x70\xaa\xb7\x8d" "\x1f\x64\x32\x1b\x29\x11\xff\x2d\xcb\x7f\x1a\x9e\x40\x9e\x0b\x11\x50" "\x5f\xe8\x4c\xe7\x8e\x17\xee\x88\xd0\x3f\x2e\xf7\x7d\xd1\x34\xf1\x42" "\x99\x70\x3e\xf6\x37\xc5\xba\x6b\x33\x63\xd8\x60\x42\x87\x83\x4c\x4e" "\x9a", 256); *(uint16_t*)0x20000674 = 0x14; *(uint16_t*)0x20000676 = 1; *(uint32_t*)0x20000678 = 0; *(uint32_t*)0x2000067c = 0; *(uint32_t*)0x20000680 = 0; *(uint8_t*)0x20000684 = 0; *(uint8_t*)0x20000685 = 0; *(uint8_t*)0x20000686 = 0; *(uint8_t*)0x20000687 = 0; *(uint64_t*)0x20000088 = 0x148; *(uint64_t*)0x20000258 = 1; *(uint64_t*)0x20000260 = 0; *(uint64_t*)0x20000268 = 0; *(uint32_t*)0x20000270 = 0; syscall(__NR_sendmsg, r[1], 0x20000240, 0); *(uint64_t*)0x200000c0 = 0; *(uint32_t*)0x200000c8 = 0xfffffffb; *(uint64_t*)0x200000d0 = 0x20000080; *(uint64_t*)0x20000080 = 0x20000300; memcpy((void*)0x20000300, "\x24\x00\x00\x00\x29\x00\x01\x00\xef\x00\x59\x12" "\x65\x00\x00\x00\x00\x00\x00\x00", 20); *(uint32_t*)0x20000314 = r[3]; memcpy((void*)0x20000318, "\xf4\xff\x00\x00\x00\x00\x00\x00\x04\x00\x00\x00", 12); *(uint64_t*)0x20000088 = 0xb5; *(uint64_t*)0x200000d8 = 1; *(uint64_t*)0x200000e0 = 0; *(uint64_t*)0x200000e8 = 0; *(uint32_t*)0x200000f0 = 0; syscall(__NR_sendmsg, r[0], 0x200000c0, 0); } int main(void) { syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); do_sandbox_none(); return 0; }