// https://syzkaller.appspot.com/bug?id=df4f17e2c28d3dea6a0ff7598304e55f5ebe292a // 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 #ifndef __NR_bpf #define __NR_bpf 321 #endif 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 int runcmdline(char* cmdline) { int ret = system(cmdline); if (ret) { } return ret; } static void setup_gadgetfs(); static void setup_binderfs(); static void setup_fusectl(); static void sandbox_common_mount_tmpfs(void) { write_file("/proc/sys/fs/mount-max", "100000"); if (mkdir("./syz-tmp", 0777)) exit(1); if (mount("", "./syz-tmp", "tmpfs", 0, NULL)) exit(1); if (mkdir("./syz-tmp/newroot", 0777)) exit(1); if (mkdir("./syz-tmp/newroot/dev", 0700)) exit(1); unsigned bind_mount_flags = MS_BIND | MS_REC | MS_PRIVATE; if (mount("/dev", "./syz-tmp/newroot/dev", NULL, bind_mount_flags, NULL)) exit(1); if (mkdir("./syz-tmp/newroot/proc", 0700)) exit(1); if (mount("syz-proc", "./syz-tmp/newroot/proc", "proc", 0, NULL)) exit(1); if (mkdir("./syz-tmp/newroot/selinux", 0700)) exit(1); const char* selinux_path = "./syz-tmp/newroot/selinux"; if (mount("/selinux", selinux_path, NULL, bind_mount_flags, NULL)) { if (errno != ENOENT) exit(1); if (mount("/sys/fs/selinux", selinux_path, NULL, bind_mount_flags, NULL) && errno != ENOENT) exit(1); } if (mkdir("./syz-tmp/newroot/sys", 0700)) exit(1); if (mount("/sys", "./syz-tmp/newroot/sys", 0, bind_mount_flags, NULL)) exit(1); if (mount("/sys/kernel/debug", "./syz-tmp/newroot/sys/kernel/debug", NULL, bind_mount_flags, NULL) && errno != ENOENT) exit(1); if (mount("/sys/fs/smackfs", "./syz-tmp/newroot/sys/fs/smackfs", NULL, bind_mount_flags, NULL) && errno != ENOENT) exit(1); if (mount("/proc/sys/fs/binfmt_misc", "./syz-tmp/newroot/proc/sys/fs/binfmt_misc", NULL, bind_mount_flags, NULL) && errno != ENOENT) exit(1); if (mkdir("./syz-tmp/newroot/syz-inputs", 0700)) exit(1); if (mount("/syz-inputs", "./syz-tmp/newroot/syz-inputs", NULL, bind_mount_flags | MS_RDONLY, NULL) && errno != ENOENT) exit(1); if (mkdir("./syz-tmp/pivot", 0777)) exit(1); if (syscall(SYS_pivot_root, "./syz-tmp", "./syz-tmp/pivot")) { if (chdir("./syz-tmp")) exit(1); } else { if (chdir("/")) exit(1); if (umount2("./pivot", MNT_DETACH)) exit(1); } if (chroot("./newroot")) exit(1); if (chdir("/")) exit(1); setup_gadgetfs(); setup_binderfs(); setup_fusectl(); } static void setup_gadgetfs() { if (mkdir("/dev/gadgetfs", 0777)) { } if (mount("gadgetfs", "/dev/gadgetfs", "gadgetfs", 0, NULL)) { } } static void setup_fusectl() { 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); if (getppid() == 1) exit(1); 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); sandbox_common(); drop_caps(); if (unshare(CLONE_NEWNET)) { } write_file("/proc/sys/net/ipv4/ping_group_range", "0 65535"); sandbox_common_mount_tmpfs(); loop(); exit(1); } #define SWAP_FILE "./swap-file" #define SWAP_FILE_SIZE (128 * 1000 * 1000) static const char* setup_swap() { swapoff(SWAP_FILE); unlink(SWAP_FILE); int fd = open(SWAP_FILE, O_CREAT | O_WRONLY | O_CLOEXEC, 0600); if (fd == -1) return "swap file open failed"; fallocate(fd, FALLOC_FL_ZERO_RANGE, 0, SWAP_FILE_SIZE); close(fd); char cmdline[64]; sprintf(cmdline, "mkswap %s", SWAP_FILE); if (runcmdline(cmdline)) return "mkswap failed"; if (swapon(SWAP_FILE, SWAP_FLAG_PREFER) == 1) return "swapon failed"; return NULL; } uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff}; void loop(void) { intptr_t res = 0; if (write(1, "executing program\n", sizeof("executing program\n") - 1)) { } // bpf$MAP_CREATE arguments: [ // cmd: const = 0x0 (8 bytes) // arg: ptr[in, bpf_map_create_arg] { // union bpf_map_create_arg { // base: bpf_map_create_arg_t[flags[bpf_map_type, int32], int32, int32, // int32, flags[map_flags, int32], const[0, int64]] { // type: bpf_map_type = 0x1b (4 bytes) // ksize: int32 = 0x0 (4 bytes) // vsize: int32 = 0x0 (4 bytes) // max: int32 = 0x8000 (4 bytes) // flags: map_flags = 0x0 (4 bytes) // inner: fd_bpf_map (resource) // node: int32 = 0x0 (4 bytes) // map_name: buffer: {00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 // 00} (length 0x10) map_ifindex: ifindex (resource) btf_fd: fd_btf // (resource) btf_key_type_id: int32 = 0x0 (4 bytes) // btf_value_type_id: int32 = 0x0 (4 bytes) // btf_vmlinux_type_id: int32 = 0x0 (4 bytes) // map_extra: const = 0x0 (8 bytes) // value_type_btf_obj_fd: union // _bpf_map_create_arg_t[flags[bpf_map_type, int32], int32, int32, // int32, flags[map_flags, int32], const[0, // int64]]_value_type_btf_obj_fd_wrapper { // void: buffer: {} (length 0x0) // } // pad1: union _bpf_map_create_arg_t[flags[bpf_map_type, int32], // int32, int32, int32, flags[map_flags, int32], const[0, // int64]]_pad1_wrapper { // value: const = 0x0 (4 bytes) // } // map_token_fd: union _bpf_map_create_arg_t[flags[bpf_map_type, // int32], int32, int32, int32, flags[map_flags, int32], const[0, // int64]]_map_token_fd_wrapper { // void: buffer: {} (length 0x0) // } // pad2: union _bpf_map_create_arg_t[flags[bpf_map_type, int32], // int32, int32, int32, flags[map_flags, int32], const[0, // int64]]_pad2_wrapper { // value: const = 0x0 (4 bytes) // } // } // } // } // size: len = 0x48 (8 bytes) // ] // returns fd_bpf_map *(uint32_t*)0x2000000000c0 = 0x1b; *(uint32_t*)0x2000000000c4 = 0; *(uint32_t*)0x2000000000c8 = 0; *(uint32_t*)0x2000000000cc = 0x8000; *(uint32_t*)0x2000000000d0 = 0; *(uint32_t*)0x2000000000d4 = -1; *(uint32_t*)0x2000000000d8 = 0; memset((void*)0x2000000000dc, 0, 16); *(uint32_t*)0x2000000000ec = 0; *(uint32_t*)0x2000000000f0 = -1; *(uint32_t*)0x2000000000f4 = 0; *(uint32_t*)0x2000000000f8 = 0; *(uint32_t*)0x2000000000fc = 0; *(uint64_t*)0x200000000100 = 0; *(uint32_t*)0x200000000108 = 0; *(uint32_t*)0x20000000010c = 0; res = syscall(__NR_bpf, /*cmd=*/0ul, /*arg=*/0x2000000000c0ul, /*size=*/0x48ul); if (res != -1) r[0] = res; // bpf$PROG_LOAD arguments: [ // cmd: const = 0x5 (8 bytes) // arg: ptr[in, bpf_prog_t[flags[bpf_prog_type, int32], // bpf_prog_attach_types, bpf_btf_id[opt], fd_bpf_prog[opt]]] { // bpf_prog_t[flags[bpf_prog_type, int32], bpf_prog_attach_types, // bpf_btf_id[opt], fd_bpf_prog[opt]] { // type: bpf_prog_type = 0x0 (4 bytes) // ninsn: bytesize8 = 0xc (4 bytes) // insns: ptr[inout, array[ANYUNION]] { // array[ANYUNION] { // union ANYUNION { // ANYBLOB: buffer: {18 00 00 00 00 00 00 00 00 00 00 00 00 00 00 // 00 18 12 00 00} (length 0x14) // } // union ANYUNION { // ANYRES32: ANYRES32 (resource) // } // union ANYUNION { // ANYBLOB: buffer: {00 00 00 00 00 00 00 00 b7 08 00 00 00 00 00 // 00 7b 8a f8 ff 00 00 00 00 bf a2 00 00 00 00 00 00 07 02 00 00 // f8 ff ff ff b7 03 00 00 08 00 00 00 b7 04 00 00 02 01 00 00 85 // 00 00 00 43 00 00 00 95} (length 0x41) // } // } // } // license: nil // loglev: int32 = 0x0 (4 bytes) // logsize: len = 0x0 (4 bytes) // log: nil // kern_version: bpf_kern_version = 0x0 (4 bytes) // flags: bpf_prog_load_flags = 0x0 (4 bytes) // prog_name: buffer: {00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00} // (length 0x10) prog_ifindex: ifindex (resource) expected_attach_type: // union bpf_prog_attach_types { // fallback: bpf_attach_types = 0x0 (4 bytes) // } // btf_fd: fd_btf (resource) // func_info_rec_size: const = 0x0 (4 bytes) // func_info: nil // func_info_cnt: len = 0x0 (4 bytes) // line_info_rec_size: const = 0x0 (4 bytes) // line_info: nil // line_info_cnt: len = 0x0 (4 bytes) // attach_btf_id: bpf_btf_id (resource) // attach_prog_fd: fd_bpf_prog (resource) // core_relo_cnt: len = 0x0 (4 bytes) // fd_array: nil // core_relos: nil // core_relo_rec_size: const = 0x0 (4 bytes) // log_true_size: int32 = 0x0 (4 bytes) // prog_token_fd: union _bpf_prog_t[flags[bpf_prog_type, int32], // bpf_prog_attach_types, bpf_btf_id[opt], // fd_bpf_prog[opt]]_prog_token_fd_wrapper { // void: buffer: {} (length 0x0) // } // pad: union _bpf_prog_t[flags[bpf_prog_type, int32], // bpf_prog_attach_types, bpf_btf_id[opt], // fd_bpf_prog[opt]]_pad_wrapper { // value: const = 0x0 (4 bytes) // } // } // } // size: len = 0x90 (8 bytes) // ] // returns fd_bpf_prog *(uint32_t*)0x2000000000c0 = 0; *(uint32_t*)0x2000000000c4 = 0xc; *(uint64_t*)0x2000000000c8 = 0x200000000440; memcpy((void*)0x200000000440, "\x18\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x18" "\x12\x00\x00", 20); *(uint32_t*)0x200000000454 = r[0]; memcpy((void*)0x200000000458, "\x00\x00\x00\x00\x00\x00\x00\x00\xb7\x08\x00\x00\x00\x00\x00\x00\x7b" "\x8a\xf8\xff\x00\x00\x00\x00\xbf\xa2\x00\x00\x00\x00\x00\x00\x07\x02" "\x00\x00\xf8\xff\xff\xff\xb7\x03\x00\x00\x08\x00\x00\x00\xb7\x04\x00" "\x00\x02\x01\x00\x00\x85\x00\x00\x00\x43\x00\x00\x00\x95", 65); *(uint64_t*)0x2000000000d0 = 0; *(uint32_t*)0x2000000000d8 = 0; *(uint32_t*)0x2000000000dc = 0; *(uint64_t*)0x2000000000e0 = 0; *(uint32_t*)0x2000000000e8 = 0; *(uint32_t*)0x2000000000ec = 0; memset((void*)0x2000000000f0, 0, 16); *(uint32_t*)0x200000000100 = 0; *(uint32_t*)0x200000000104 = 0; *(uint32_t*)0x200000000108 = -1; *(uint32_t*)0x20000000010c = 0; *(uint64_t*)0x200000000110 = 0; *(uint32_t*)0x200000000118 = 0; *(uint32_t*)0x20000000011c = 0; *(uint64_t*)0x200000000120 = 0; *(uint32_t*)0x200000000128 = 0; *(uint32_t*)0x20000000012c = 0; *(uint32_t*)0x200000000130 = 0; *(uint32_t*)0x200000000134 = 0; *(uint64_t*)0x200000000138 = 0; *(uint64_t*)0x200000000140 = 0; *(uint32_t*)0x200000000148 = 0; *(uint32_t*)0x20000000014c = 0; *(uint32_t*)0x200000000150 = 0; syscall(__NR_bpf, /*cmd=*/5ul, /*arg=*/0x2000000000c0ul, /*size=*/0x90ul); // bpf$PROG_LOAD arguments: [ // cmd: const = 0x5 (8 bytes) // arg: ptr[in, bpf_prog_t[flags[bpf_prog_type, int32], // bpf_prog_attach_types, bpf_btf_id[opt], fd_bpf_prog[opt]]] { // bpf_prog_t[flags[bpf_prog_type, int32], bpf_prog_attach_types, // bpf_btf_id[opt], fd_bpf_prog[opt]] { // type: bpf_prog_type = 0x1f (4 bytes) // ninsn: bytesize8 = 0xc (4 bytes) // insns: ptr[inout, array[ANYUNION]] { // array[ANYUNION] { // } // } // license: ptr[in, buffer] { // buffer: {47 50 4c 00} (length 0x4) // } // loglev: int32 = 0x0 (4 bytes) // logsize: len = 0x0 (4 bytes) // log: nil // kern_version: bpf_kern_version = 0x0 (4 bytes) // flags: bpf_prog_load_flags = 0x12 (4 bytes) // prog_name: buffer: {00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00} // (length 0x10) prog_ifindex: ifindex (resource) expected_attach_type: // union bpf_prog_attach_types { // fallback: bpf_attach_types = 0x0 (4 bytes) // } // btf_fd: fd_btf (resource) // func_info_rec_size: const = 0x0 (4 bytes) // func_info: nil // func_info_cnt: len = 0x0 (4 bytes) // line_info_rec_size: const = 0x0 (4 bytes) // line_info: nil // line_info_cnt: len = 0x0 (4 bytes) // attach_btf_id: bpf_btf_id (resource) // attach_prog_fd: fd_bpf_prog (resource) // core_relo_cnt: len = 0x0 (4 bytes) // fd_array: nil // core_relos: nil // core_relo_rec_size: const = 0x0 (4 bytes) // log_true_size: int32 = 0x0 (4 bytes) // prog_token_fd: union _bpf_prog_t[flags[bpf_prog_type, int32], // bpf_prog_attach_types, bpf_btf_id[opt], // fd_bpf_prog[opt]]_prog_token_fd_wrapper { // void: buffer: {} (length 0x0) // } // pad: union _bpf_prog_t[flags[bpf_prog_type, int32], // bpf_prog_attach_types, bpf_btf_id[opt], // fd_bpf_prog[opt]]_pad_wrapper { // value: const = 0x0 (4 bytes) // } // } // } // size: len = 0x90 (8 bytes) // ] // returns fd_bpf_prog *(uint32_t*)0x2000000000c0 = 0x1f; *(uint32_t*)0x2000000000c4 = 0xc; *(uint64_t*)0x2000000000c8 = 0x200000000440; *(uint64_t*)0x2000000000d0 = 0x200000000240; memcpy((void*)0x200000000240, "GPL\000", 4); *(uint32_t*)0x2000000000d8 = 0; *(uint32_t*)0x2000000000dc = 0; *(uint64_t*)0x2000000000e0 = 0; *(uint32_t*)0x2000000000e8 = 0; *(uint32_t*)0x2000000000ec = 0x12; memset((void*)0x2000000000f0, 0, 16); *(uint32_t*)0x200000000100 = 0; *(uint32_t*)0x200000000104 = 0; *(uint32_t*)0x200000000108 = -1; *(uint32_t*)0x20000000010c = 0; *(uint64_t*)0x200000000110 = 0; *(uint32_t*)0x200000000118 = 0; *(uint32_t*)0x20000000011c = 0; *(uint64_t*)0x200000000120 = 0; *(uint32_t*)0x200000000128 = 0; *(uint32_t*)0x20000000012c = 0; *(uint32_t*)0x200000000130 = 0; *(uint32_t*)0x200000000134 = 0; *(uint64_t*)0x200000000138 = 0; *(uint64_t*)0x200000000140 = 0; *(uint32_t*)0x200000000148 = 0; *(uint32_t*)0x20000000014c = 0; *(uint32_t*)0x200000000150 = 0; res = syscall(__NR_bpf, /*cmd=*/5ul, /*arg=*/0x2000000000c0ul, /*size=*/0x90ul); if (res != -1) r[1] = res; // bpf$BPF_GET_PROG_INFO arguments: [ // cmd: const = 0xa (8 bytes) // arg: ptr[in, bpf_get_prog_info_arg] { // bpf_get_prog_info_arg { // prog: fd_bpf_prog (resource) // len: len = 0x0 (4 bytes) // info: nil // } // } // size: len = 0x10 (8 bytes) // ] *(uint32_t*)0x200000000740 = r[1]; *(uint32_t*)0x200000000744 = 0; *(uint64_t*)0x200000000748 = 0; syscall(__NR_bpf, /*cmd=*/0xaul, /*arg=*/0x200000000740ul, /*size=*/0x10ul); } int main(void) { syscall(__NR_mmap, /*addr=*/0x1ffffffff000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x200000000000ul, /*len=*/0x1000000ul, /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/ 7ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x200001000000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul); const char* reason; (void)reason; if ((reason = setup_swap())) printf("the reproducer may not work as expected: swap setup failed: %s\n", reason); do_sandbox_none(); return 0; }