// https://syzkaller.appspot.com/bug?id=9560fbabf0007656f8f62b02bf77fe2ebabc6678 // 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 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 = 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); } static void close_fds() { for (int fd = 3; fd < MAX_FDS; fd++) close(fd); } uint64_t r[3] = {0x0, 0xffffffffffffffff, 0xffffffffffffffff}; void loop(void) { intptr_t res = 0; *(uint64_t*)0x20000140 = 8; *(uint64_t*)0x20000148 = 0x8b; syscall(__NR_prlimit64, 0, 0xeul, 0x20000140ul, 0ul); res = syscall(__NR_getpid); if (res != -1) r[0] = res; *(uint32_t*)0x20001700 = 4; syscall(__NR_sched_setscheduler, r[0], 1ul, 0x20001700ul); syscall(__NR_sendmmsg, -1, 0ul, 0ul, 0ul); syscall(__NR_recvmmsg, -1, 0ul, 0ul, 2ul, 0ul); syscall(__NR_mkdir, 0ul, 0ul); memcpy((void*)0x20000140, "/dev/vim2m\000", 11); res = syscall(__NR_openat, 0xffffffffffffff9cul, 0x20000140ul, 2ul, 0ul); if (res != -1) r[1] = res; *(uint32_t*)0x20000040 = 0xa5; *(uint32_t*)0x20000044 = 1; *(uint32_t*)0x20000048 = 1; *(uint32_t*)0x2000004c = 0; *(uint8_t*)0x20000050 = 0; memset((void*)0x20000051, 0, 3); syscall(__NR_ioctl, r[1], 0xc0145608, 0x20000040ul); *(uint32_t*)0x200000c0 = 0xffffffe0; *(uint32_t*)0x200000c4 = 2; *(uint32_t*)0x200000c8 = 1; *(uint32_t*)0x200000cc = 0; *(uint8_t*)0x200000d0 = 0; memset((void*)0x200000d1, 0, 3); syscall(__NR_ioctl, r[1], 0xc0145608, 0x200000c0ul); *(uint32_t*)0x20000000 = 1; syscall(__NR_ioctl, r[1], 0x40045612, 0x20000000ul); *(uint32_t*)0x20000080 = 2; syscall(__NR_ioctl, r[1], 0x40045612, 0x20000080ul); *(uint32_t*)0x20000400 = 0; *(uint32_t*)0x20000404 = 1; *(uint32_t*)0x20000408 = 4; *(uint32_t*)0x2000040c = 0; *(uint32_t*)0x20000410 = 0; *(uint64_t*)0x20000418 = 0; *(uint64_t*)0x20000420 = 0; *(uint32_t*)0x20000428 = 0; *(uint32_t*)0x2000042c = 0; *(uint8_t*)0x20000430 = 0; *(uint8_t*)0x20000431 = 0; *(uint8_t*)0x20000432 = 0; *(uint8_t*)0x20000433 = 0; memcpy((void*)0x20000434, "\x77\x16\x91\x3e", 4); *(uint32_t*)0x20000438 = 0; *(uint32_t*)0x2000043c = 1; *(uint64_t*)0x20000440 = 0; *(uint32_t*)0x20000448 = 0; *(uint32_t*)0x2000044c = 0; *(uint32_t*)0x20000450 = -1; syscall(__NR_ioctl, r[1], 0xc058560f, 0x20000400ul); *(uint32_t*)0x20000300 = 0; *(uint32_t*)0x20000304 = 2; *(uint32_t*)0x20000308 = 4; *(uint32_t*)0x2000030c = 0; *(uint32_t*)0x20000310 = 0; *(uint64_t*)0x20000318 = 0x77359400; *(uint64_t*)0x20000320 = 0; *(uint32_t*)0x20000328 = 0; *(uint32_t*)0x2000032c = 0; *(uint8_t*)0x20000330 = 0; *(uint8_t*)0x20000331 = 0; *(uint8_t*)0x20000332 = 0; *(uint8_t*)0x20000333 = 0; memcpy((void*)0x20000334, "\x80\x62\x5a\xba", 4); *(uint32_t*)0x20000338 = 0; *(uint32_t*)0x2000033c = 1; *(uint64_t*)0x20000340 = 0; *(uint32_t*)0x20000348 = 0; *(uint32_t*)0x2000034c = 0; *(uint32_t*)0x20000350 = -1; syscall(__NR_ioctl, r[1], 0xc058560f, 0x20000300ul); syscall(__NR_sendmmsg, -1, 0ul, 0ul, 0ul); res = syscall(__NR_open, 0ul, 0ul, 0ul); if (res != -1) r[2] = res; syscall(__NR_openat, r[2], 0ul, 2ul, 0ul); close_fds(); } 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; }