| // BUG: Dentry still in use [unmount of sysfs sysfs] |
| // https://syzkaller.appspot.com/bug?id=2dbce17f865f34c37da63de733f31001f293d78f |
| // status:fixed |
| // autogenerated by syzkaller (https://github.com/google/syzkaller) |
| |
| #define _GNU_SOURCE |
| |
| #include <endian.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <sched.h> |
| #include <stdarg.h> |
| #include <stdbool.h> |
| #include <stdint.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/mount.h> |
| #include <sys/prctl.h> |
| #include <sys/resource.h> |
| #include <sys/stat.h> |
| #include <sys/syscall.h> |
| #include <sys/time.h> |
| #include <sys/types.h> |
| #include <sys/wait.h> |
| #include <unistd.h> |
| |
| 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 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); |
| } |
| |
| static void close_fds() |
| { |
| int fd; |
| for (fd = 3; fd < 30; fd++) |
| close(fd); |
| } |
| |
| #ifndef __NR_fsconfig |
| #define __NR_fsconfig 431 |
| #endif |
| #ifndef __NR_fsmount |
| #define __NR_fsmount 432 |
| #endif |
| #ifndef __NR_fsopen |
| #define __NR_fsopen 430 |
| #endif |
| |
| uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff}; |
| |
| void loop(void) |
| { |
| intptr_t res = 0; |
| memcpy((void*)0x20000040, "sysfs\000", 6); |
| res = syscall(__NR_fsopen, 0x20000040, 0); |
| if (res != -1) |
| r[0] = res; |
| syscall(__NR_fsconfig, r[0], 6, 0, 0, 0); |
| res = syscall(__NR_fsmount, r[0], 0, 0); |
| if (res != -1) |
| r[1] = res; |
| syscall(__NR_fchdir, r[1]); |
| close_fds(); |
| } |
| int main(void) |
| { |
| syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); |
| do_sandbox_none(); |
| return 0; |
| } |