// https://syzkaller.appspot.com/bug?id=4cb6430631b7567848a6736be59d0350b3ada2ea // 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 #include unsigned long long procid; static void sleep_ms(uint64_t ms) { usleep(ms * 1000); } static uint64_t current_time_ms(void) { struct timespec ts; if (clock_gettime(CLOCK_MONOTONIC, &ts)) exit(1); return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000; } static void use_temporary_dir(void) { char tmpdir_template[] = "./syzkaller.XXXXXX"; char* tmpdir = mkdtemp(tmpdir_template); if (!tmpdir) exit(1); if (chmod(tmpdir, 0777)) exit(1); if (chdir(tmpdir)) exit(1); } 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_cgroups() { if (mkdir("/syzcgroup", 0777)) { } if (mkdir("/syzcgroup/unified", 0777)) { } if (mount("none", "/syzcgroup/unified", "cgroup2", 0, NULL)) { } if (chmod("/syzcgroup/unified", 0777)) { } if (!write_file("/syzcgroup/unified/cgroup.subtree_control", "+cpu +memory +io +pids +rdma")) { } if (mkdir("/syzcgroup/cpu", 0777)) { } if (mount("none", "/syzcgroup/cpu", "cgroup", 0, "cpuset,cpuacct,perf_event,hugetlb")) { } if (!write_file("/syzcgroup/cpu/cgroup.clone_children", "1")) { } if (chmod("/syzcgroup/cpu", 0777)) { } if (mkdir("/syzcgroup/net", 0777)) { } if (mount("none", "/syzcgroup/net", "cgroup", 0, "net_cls,net_prio,devices,freezer")) { } if (chmod("/syzcgroup/net", 0777)) { } } static void setup_binfmt_misc() { if (mount(0, "/proc/sys/fs/binfmt_misc", "binfmt_misc", 0, 0)) { } if (!write_file("/proc/sys/fs/binfmt_misc/register", ":syz0:M:0:\x01::./file0:")) { } if (!write_file("/proc/sys/fs/binfmt_misc/register", ":syz1:M:1:\x02::./file0:POC")) { } } static void setup_common() { if (mount(0, "/sys/fs/fuse/connections", "fusectl", 0, 0)) { } setup_cgroups(); setup_binfmt_misc(); } 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)) { } } int wait_for_loop(int pid) { if (pid < 0) exit(1); int status = 0; while (waitpid(-1, &status, __WALL) != pid) { } return WEXITSTATUS(status); } 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(); if (unshare(CLONE_NEWNET)) { } loop(); exit(1); } #define FS_IOC_SETFLAGS _IOW('f', 2, long) static void remove_dir(const char* dir) { DIR* dp; struct dirent* ep; int iter = 0; retry: while (umount2(dir, MNT_DETACH) == 0) { } dp = opendir(dir); if (dp == NULL) { if (errno == EMFILE) { exit(1); } exit(1); } while ((ep = readdir(dp))) { if (strcmp(ep->d_name, ".") == 0 || strcmp(ep->d_name, "..") == 0) continue; char filename[FILENAME_MAX]; snprintf(filename, sizeof(filename), "%s/%s", dir, ep->d_name); while (umount2(filename, MNT_DETACH) == 0) { } struct stat st; if (lstat(filename, &st)) exit(1); if (S_ISDIR(st.st_mode)) { remove_dir(filename); continue; } int i; for (i = 0;; i++) { if (unlink(filename) == 0) break; if (errno == EPERM) { int fd = open(filename, O_RDONLY); if (fd != -1) { long flags = 0; if (ioctl(fd, FS_IOC_SETFLAGS, &flags) == 0) close(fd); continue; } } if (errno == EROFS) { break; } if (errno != EBUSY || i > 100) exit(1); if (umount2(filename, MNT_DETACH)) exit(1); } } closedir(dp); int i; for (i = 0;; i++) { if (rmdir(dir) == 0) break; if (i < 100) { if (errno == EPERM) { int fd = open(dir, O_RDONLY); if (fd != -1) { long flags = 0; if (ioctl(fd, FS_IOC_SETFLAGS, &flags) == 0) close(fd); continue; } } if (errno == EROFS) { break; } if (errno == EBUSY) { if (umount2(dir, MNT_DETACH)) exit(1); continue; } if (errno == ENOTEMPTY) { if (iter < 100) { iter++; goto retry; } } } exit(1); } } static void kill_and_wait(int pid, int* status) { kill(-pid, SIGKILL); kill(pid, SIGKILL); int i; for (i = 0; i < 100; i++) { if (waitpid(-1, status, WNOHANG | __WALL) == pid) return; usleep(1000); } DIR* dir = opendir("/sys/fs/fuse/connections"); if (dir) { for (;;) { struct dirent* ent = readdir(dir); if (!ent) break; if (strcmp(ent->d_name, ".") == 0 || strcmp(ent->d_name, "..") == 0) continue; char abort[300]; snprintf(abort, sizeof(abort), "/sys/fs/fuse/connections/%s/abort", ent->d_name); int fd = open(abort, O_WRONLY); if (fd == -1) { continue; } if (write(fd, abort, 1) < 0) { } close(fd); } closedir(dir); } else { } while (waitpid(-1, status, __WALL) != pid) { } } #define SYZ_HAVE_SETUP_LOOP 1 static void setup_loop() { int pid = getpid(); char cgroupdir[64]; char file[128]; snprintf(cgroupdir, sizeof(cgroupdir), "/syzcgroup/unified/syz%llu", procid); if (mkdir(cgroupdir, 0777)) { } snprintf(file, sizeof(file), "%s/pids.max", cgroupdir); if (!write_file(file, "32")) { } snprintf(file, sizeof(file), "%s/memory.low", cgroupdir); if (!write_file(file, "%d", 298 << 20)) { } snprintf(file, sizeof(file), "%s/memory.high", cgroupdir); if (!write_file(file, "%d", 299 << 20)) { } snprintf(file, sizeof(file), "%s/memory.max", cgroupdir); if (!write_file(file, "%d", 300 << 20)) { } snprintf(file, sizeof(file), "%s/cgroup.procs", cgroupdir); if (!write_file(file, "%d", pid)) { } snprintf(cgroupdir, sizeof(cgroupdir), "/syzcgroup/cpu/syz%llu", procid); if (mkdir(cgroupdir, 0777)) { } snprintf(file, sizeof(file), "%s/cgroup.procs", cgroupdir); if (!write_file(file, "%d", pid)) { } snprintf(cgroupdir, sizeof(cgroupdir), "/syzcgroup/net/syz%llu", procid); if (mkdir(cgroupdir, 0777)) { } snprintf(file, sizeof(file), "%s/cgroup.procs", cgroupdir); if (!write_file(file, "%d", pid)) { } } #define SYZ_HAVE_SETUP_TEST 1 static void setup_test() { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); char cgroupdir[64]; snprintf(cgroupdir, sizeof(cgroupdir), "/syzcgroup/unified/syz%llu", procid); if (symlink(cgroupdir, "./cgroup")) { } snprintf(cgroupdir, sizeof(cgroupdir), "/syzcgroup/cpu/syz%llu", procid); if (symlink(cgroupdir, "./cgroup.cpu")) { } snprintf(cgroupdir, sizeof(cgroupdir), "/syzcgroup/net/syz%llu", procid); if (symlink(cgroupdir, "./cgroup.net")) { } if (!write_file("/proc/self/oom_score_adj", "1000")) { } } #define SYZ_HAVE_RESET_TEST 1 static void reset_test() { int fd; for (fd = 3; fd < 30; fd++) close(fd); } static void execute_one(void); #define WAIT_FLAGS __WALL static void loop(void) { setup_loop(); int iter; for (iter = 0;; iter++) { char cwdbuf[32]; sprintf(cwdbuf, "./%d", iter); if (mkdir(cwdbuf, 0777)) exit(1); int pid = fork(); if (pid < 0) exit(1); if (pid == 0) { if (chdir(cwdbuf)) exit(1); setup_test(); execute_one(); reset_test(); exit(0); } int status = 0; uint64_t start = current_time_ms(); for (;;) { if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid) break; sleep_ms(1); if (current_time_ms() - start < 5 * 1000) continue; kill_and_wait(pid, &status); break; } remove_dir(cwdbuf); } } uint64_t r[4] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff}; void execute_one(void) { long res = 0; *(uint8_t*)0x20000180 = 0x2b; memcpy((void*)0x20000181, "cpu", 3); *(uint8_t*)0x20000184 = 0x20; *(uint8_t*)0x20000185 = 0x2f; memcpy((void*)0x20000186, "rdma", 4); *(uint8_t*)0x2000018a = 0x20; *(uint8_t*)0x2000018b = 0x2b; memcpy((void*)0x2000018c, "pids", 4); *(uint8_t*)0x20000190 = 0x20; *(uint8_t*)0x20000191 = 0x2b; memcpy((void*)0x20000192, "rdma", 4); *(uint8_t*)0x20000196 = 0x20; *(uint8_t*)0x20000197 = 0x2f; memcpy((void*)0x20000198, "cpu", 3); *(uint8_t*)0x2000019b = 0x20; *(uint8_t*)0x2000019c = 0x2b; memcpy((void*)0x2000019d, "rdma", 4); *(uint8_t*)0x200001a1 = 0x20; *(uint8_t*)0x200001a2 = 0x2f; memcpy((void*)0x200001a3, "memory", 6); *(uint8_t*)0x200001a9 = 0x20; *(uint8_t*)0x200001aa = 0x2f; memcpy((void*)0x200001ab, "pids", 4); *(uint8_t*)0x200001af = 0x20; syscall(__NR_write, -1, 0x20000180, 0x30); memcpy((void*)0x200003c0, "./cgroup/syz0", 14); res = syscall(__NR_openat, 0xffffffffffffff9c, 0x200003c0, 0x200002, 0); if (res != -1) r[0] = res; memcpy((void*)0x20000000, "./cgroup", 9); res = syscall(__NR_openat, 0xffffffffffffff9c, 0x20000000, 0x200002, 0); if (res != -1) r[1] = res; memcpy((void*)0x200000c0, "cgroup.subtree_control", 23); res = syscall(__NR_openat, r[1], 0x200000c0, 2, 0); if (res != -1) r[2] = res; *(uint8_t*)0x20000080 = 0x2b; memcpy((void*)0x20000081, "pids", 4); *(uint8_t*)0x20000085 = 0x20; syscall(__NR_write, r[2], 0x20000080, 6); *(uint8_t*)0x20000100 = 0x2d; memcpy((void*)0x20000101, "pids", 4); *(uint8_t*)0x20000105 = 0x20; syscall(__NR_write, r[2], 0x20000100, 6); memcpy((void*)0x20000000, "cgroup.type", 12); res = syscall(__NR_openat, r[0], 0x20000000, 2, 0); if (res != -1) r[3] = res; memcpy((void*)0x20000140, "threaded", 9); syscall(__NR_write, r[3], 0x20000140, 9); memcpy((void*)0x20000240, "./cgroup/syz0", 14); syscall(__NR_mkdirat, 0xffffffffffffff9c, 0x20000240, 0x1ff); } int main(void) { syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); use_temporary_dir(); do_sandbox_none(); return 0; }