// https://syzkaller.appspot.com/bug?id=892ad90d74b324e4b35fa23c4ac6602b76b59573 // 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 #ifndef __NR_bpf #define __NR_bpf 321 #endif #define BITMASK(bf_off, bf_len) (((1ull << (bf_len)) - 1) << (bf_off)) #define STORE_BY_BITMASK(type, htobe, addr, val, bf_off, bf_len) \ *(type*)(addr) = \ htobe((htobe(*(type*)(addr)) & ~BITMASK((bf_off), (bf_len))) | \ (((type)(val) << (bf_off)) & BITMASK((bf_off), (bf_len)))) 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_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/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_binderfs(); setup_fusectl(); } 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); } uint64_t r[3] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff}; void loop(void) { intptr_t res = 0; if (write(1, "executing program\n", sizeof("executing program\n") - 1)) { } *(uint32_t*)0x20000840 = 0xb; *(uint32_t*)0x20000844 = 5; *(uint32_t*)0x20000848 = 2; *(uint32_t*)0x2000084c = 4; *(uint32_t*)0x20000850 = 5; *(uint32_t*)0x20000854 = -1; *(uint32_t*)0x20000858 = 0; memset((void*)0x2000085c, 0, 16); *(uint32_t*)0x2000086c = 0; *(uint32_t*)0x20000870 = -1; *(uint32_t*)0x20000874 = 0; *(uint32_t*)0x20000878 = 0; *(uint32_t*)0x2000087c = 0; *(uint64_t*)0x20000880 = 0; *(uint32_t*)0x20000888 = 0; *(uint32_t*)0x2000088c = 0; res = syscall(__NR_bpf, /*cmd=*/0ul, /*arg=*/0x20000840ul, /*size=*/0x48ul); if (res != -1) r[0] = res; *(uint32_t*)0x20000180 = 0x11; *(uint32_t*)0x20000184 = 0xc; *(uint64_t*)0x20000188 = 0x20000440; *(uint8_t*)0x20000440 = 0x18; STORE_BY_BITMASK(uint8_t, , 0x20000441, 0, 0, 4); STORE_BY_BITMASK(uint8_t, , 0x20000441, 0, 4, 4); *(uint16_t*)0x20000442 = 0; *(uint32_t*)0x20000444 = 0; *(uint8_t*)0x20000448 = 0; *(uint8_t*)0x20000449 = 0; *(uint16_t*)0x2000044a = 0; *(uint32_t*)0x2000044c = 0; *(uint8_t*)0x20000450 = 0x18; STORE_BY_BITMASK(uint8_t, , 0x20000451, 1, 0, 4); STORE_BY_BITMASK(uint8_t, , 0x20000451, 1, 4, 4); *(uint16_t*)0x20000452 = 0; *(uint32_t*)0x20000454 = r[0]; *(uint8_t*)0x20000458 = 0; *(uint8_t*)0x20000459 = 0; *(uint16_t*)0x2000045a = 0; *(uint32_t*)0x2000045c = 0; STORE_BY_BITMASK(uint8_t, , 0x20000460, 7, 0, 3); STORE_BY_BITMASK(uint8_t, , 0x20000460, 0, 3, 1); STORE_BY_BITMASK(uint8_t, , 0x20000460, 0xb, 4, 4); STORE_BY_BITMASK(uint8_t, , 0x20000461, 8, 0, 4); STORE_BY_BITMASK(uint8_t, , 0x20000461, 0, 4, 4); *(uint16_t*)0x20000462 = 0; *(uint32_t*)0x20000464 = 0; STORE_BY_BITMASK(uint8_t, , 0x20000468, 3, 0, 3); STORE_BY_BITMASK(uint8_t, , 0x20000468, 3, 3, 2); STORE_BY_BITMASK(uint8_t, , 0x20000468, 3, 5, 3); STORE_BY_BITMASK(uint8_t, , 0x20000469, 0xa, 0, 4); STORE_BY_BITMASK(uint8_t, , 0x20000469, 8, 4, 4); *(uint16_t*)0x2000046a = 0xfff8; *(uint32_t*)0x2000046c = 0; STORE_BY_BITMASK(uint8_t, , 0x20000470, 7, 0, 3); STORE_BY_BITMASK(uint8_t, , 0x20000470, 1, 3, 1); STORE_BY_BITMASK(uint8_t, , 0x20000470, 0xb, 4, 4); STORE_BY_BITMASK(uint8_t, , 0x20000471, 2, 0, 4); STORE_BY_BITMASK(uint8_t, , 0x20000471, 0xa, 4, 4); *(uint16_t*)0x20000472 = 0; *(uint32_t*)0x20000474 = 0; STORE_BY_BITMASK(uint8_t, , 0x20000478, 7, 0, 3); STORE_BY_BITMASK(uint8_t, , 0x20000478, 0, 3, 1); STORE_BY_BITMASK(uint8_t, , 0x20000478, 0, 4, 4); STORE_BY_BITMASK(uint8_t, , 0x20000479, 2, 0, 4); STORE_BY_BITMASK(uint8_t, , 0x20000479, 0, 4, 4); *(uint16_t*)0x2000047a = 0; *(uint32_t*)0x2000047c = 0xfffffff8; STORE_BY_BITMASK(uint8_t, , 0x20000480, 7, 0, 3); STORE_BY_BITMASK(uint8_t, , 0x20000480, 0, 3, 1); STORE_BY_BITMASK(uint8_t, , 0x20000480, 0xb, 4, 4); STORE_BY_BITMASK(uint8_t, , 0x20000481, 3, 0, 4); STORE_BY_BITMASK(uint8_t, , 0x20000481, 0, 4, 4); *(uint16_t*)0x20000482 = 0; *(uint32_t*)0x20000484 = 8; STORE_BY_BITMASK(uint8_t, , 0x20000488, 7, 0, 3); STORE_BY_BITMASK(uint8_t, , 0x20000488, 0, 3, 1); STORE_BY_BITMASK(uint8_t, , 0x20000488, 0xb, 4, 4); STORE_BY_BITMASK(uint8_t, , 0x20000489, 4, 0, 4); STORE_BY_BITMASK(uint8_t, , 0x20000489, 0, 4, 4); *(uint16_t*)0x2000048a = 0; *(uint32_t*)0x2000048c = 0; *(uint8_t*)0x20000490 = 0x85; *(uint8_t*)0x20000491 = 0; *(uint16_t*)0x20000492 = 0; *(uint32_t*)0x20000494 = 3; *(uint8_t*)0x20000498 = 0x95; *(uint8_t*)0x20000499 = 0; *(uint16_t*)0x2000049a = 0; *(uint32_t*)0x2000049c = 0; *(uint64_t*)0x20000190 = 0x20000100; memcpy((void*)0x20000100, "GPL\000", 4); *(uint32_t*)0x20000198 = 0; *(uint32_t*)0x2000019c = 0; *(uint64_t*)0x200001a0 = 0; *(uint32_t*)0x200001a8 = 0; *(uint32_t*)0x200001ac = 0; memset((void*)0x200001b0, 0, 16); *(uint32_t*)0x200001c0 = 0; *(uint32_t*)0x200001c4 = 0; *(uint32_t*)0x200001c8 = -1; *(uint32_t*)0x200001cc = 0; *(uint64_t*)0x200001d0 = 0; *(uint32_t*)0x200001d8 = 0; *(uint32_t*)0x200001dc = 0; *(uint64_t*)0x200001e0 = 0; *(uint32_t*)0x200001e8 = 0; *(uint32_t*)0x200001ec = 0; *(uint32_t*)0x200001f0 = 0; *(uint32_t*)0x200001f4 = 0; *(uint64_t*)0x200001f8 = 0; *(uint64_t*)0x20000200 = 0; *(uint32_t*)0x20000208 = 0; *(uint32_t*)0x2000020c = 0; *(uint32_t*)0x20000210 = 0; res = syscall(__NR_bpf, /*cmd=*/5ul, /*arg=*/0x20000180ul, /*size=*/0x90ul); if (res != -1) r[1] = res; *(uint64_t*)0x200000c0 = 0x20000080; memcpy((void*)0x20000080, "mm_page_alloc\000", 14); *(uint32_t*)0x200000c8 = r[1]; *(uint32_t*)0x200000cc = 0; *(uint64_t*)0x200000d0 = 0; syscall(__NR_bpf, /*cmd=*/0x11ul, /*arg=*/0x200000c0ul, /*size=*/0x10ul); *(uint32_t*)0x20000180 = 0xb; *(uint32_t*)0x20000184 = 9; *(uint32_t*)0x20000188 = 0x10001; *(uint32_t*)0x2000018c = 9; *(uint32_t*)0x20000190 = 1; *(uint32_t*)0x20000194 = -1; *(uint32_t*)0x20000198 = 0; memset((void*)0x2000019c, 0, 16); *(uint32_t*)0x200001ac = 0; *(uint32_t*)0x200001b0 = -1; *(uint32_t*)0x200001b4 = 0; *(uint32_t*)0x200001b8 = 0; *(uint32_t*)0x200001bc = 0; *(uint64_t*)0x200001c0 = 0; *(uint32_t*)0x200001c8 = 0; *(uint32_t*)0x200001cc = 0; res = syscall(__NR_bpf, /*cmd=*/0ul, /*arg=*/0x20000180ul, /*size=*/0x48ul); if (res != -1) r[2] = res; *(uint32_t*)0x20000940 = r[2]; *(uint64_t*)0x20000948 = 0x200008c0; *(uint32_t*)0x200008c0 = 0; *(uint64_t*)0x20000950 = 0x20000900; *(uint32_t*)0x20000900 = -1; *(uint64_t*)0x20000958 = 0; syscall(__NR_bpf, /*cmd=*/2ul, /*arg=*/0x20000940ul, /*size=*/0x20ul); } int main(void) { syscall(__NR_mmap, /*addr=*/0x1ffff000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x20000000ul, /*len=*/0x1000000ul, /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/ 7ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x21000000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1, /*offset=*/0ul); const char* reason; (void)reason; do_sandbox_none(); return 0; }