diff options
| -rw-r--r-- | pkg/rootless/rootless_linux.c | 304 |
1 files changed, 147 insertions, 157 deletions
diff --git a/pkg/rootless/rootless_linux.c b/pkg/rootless/rootless_linux.c index 44ed40ce3..e71d5d999 100644 --- a/pkg/rootless/rootless_linux.c +++ b/pkg/rootless/rootless_linux.c @@ -19,6 +19,33 @@ #include <sys/select.h> #include <stdio.h> +#define cleanup_free __attribute__ ((cleanup (cleanup_freep))) +#define cleanup_close __attribute__ ((cleanup (cleanup_closep))) +#define cleanup_dir __attribute__ ((cleanup (cleanup_dirp))) + +static inline void +cleanup_freep (void *p) +{ + void **pp = (void **) p; + free (*pp); +} + +static inline void +cleanup_closep (void *p) +{ + int *pp = p; + if (*pp >= 0) + TEMP_FAILURE_RETRY (close (*pp)); +} + +static inline void +cleanup_dirp (DIR **p) +{ + DIR *dir = *p; + if (dir) + closedir (dir); +} + int rename_noreplace (int olddirfd, const char *oldpath, int newdirfd, const char *newpath) { int ret; @@ -119,8 +146,8 @@ do_pause () static char ** get_cmd_line_args () { - int fd; - char *buffer; + cleanup_free char *buffer = NULL; + cleanup_close int fd = -1; size_t allocated; size_t used = 0; int ret; @@ -139,10 +166,7 @@ get_cmd_line_args () { ret = TEMP_FAILURE_RETRY (read (fd, buffer + used, allocated - used)); if (ret < 0) - { - free (buffer); - return NULL; - } + return NULL; if (ret == 0) break; @@ -153,30 +177,21 @@ get_cmd_line_args () allocated += 512; char *tmp = realloc (buffer, allocated); if (tmp == NULL) - { - free (buffer); - return NULL; - } + return NULL; buffer = tmp; } } - close (fd); for (i = 0; i < used; i++) if (buffer[i] == '\0') argc++; if (argc == 0) - { - free (buffer); - return NULL; - } + return NULL; argv = malloc (sizeof (char *) * (argc + 1)); if (argv == NULL) - { - free (buffer); - return NULL; - } + return NULL; + argc = 0; argv[argc++] = buffer; @@ -186,15 +201,19 @@ get_cmd_line_args () argv[argc] = NULL; + /* Move ownership. */ + buffer = NULL; + return argv; } static bool can_use_shortcut () { - int argc; - char **argv; + cleanup_free char **argv = NULL; + cleanup_free char *argv0 = NULL; bool ret = true; + int argc; #ifdef DISABLE_JOIN_SHORTCUT return false; @@ -204,12 +223,10 @@ can_use_shortcut () if (argv == NULL) return false; + argv0 = argv[0]; + if (strstr (argv[0], "podman") == NULL) - { - free (argv[0]); - free (argv); - return false; - } + return false; for (argc = 0; argv[argc]; argc++) { @@ -234,11 +251,25 @@ can_use_shortcut () } } - free (argv[0]); - free (argv); return ret; } +static int +open_namespace (int pid_to_join, const char *ns_file) +{ + char ns_path[PATH_MAX]; + int ret; + + ret = snprintf (ns_path, PATH_MAX, "/proc/%d/ns/%s", pid_to_join, ns_file); + if (ret == PATH_MAX) + { + fprintf (stderr, "internal error: namespace path too long\n"); + return -1; + } + + return open (ns_path, O_CLOEXEC | O_RDONLY); +} + int is_fd_inherited(int fd) { @@ -255,8 +286,7 @@ static void __attribute__((constructor)) init() const char *listen_pid; const char *listen_fds; const char *listen_fdnames; - - DIR *d; + cleanup_dir DIR *d = NULL; pause = getenv ("_PODMAN_PAUSE"); if (pause && pause[0]) @@ -304,7 +334,6 @@ static void __attribute__((constructor)) init() FD_SET (fd % FD_SETSIZE, &(open_files_set[fd / FD_SETSIZE])); } - closedir (d); } listen_pid = getenv("LISTEN_PID"); @@ -322,7 +351,7 @@ static void __attribute__((constructor)) init() if (saved_systemd_listen_pid == NULL || saved_systemd_listen_fds == NULL) { - fprintf (stderr, "save socket listen environments error: %s\n", strerror (errno)); + fprintf (stderr, "save socket listen environments error: %m\n"); _exit (EXIT_FAILURE); } } @@ -332,73 +361,70 @@ static void __attribute__((constructor)) init() xdg_runtime_dir = getenv ("XDG_RUNTIME_DIR"); if (geteuid () != 0 && xdg_runtime_dir && xdg_runtime_dir[0] && can_use_shortcut ()) { - int r; - int fd; + cleanup_free char *cwd = NULL; + cleanup_close int userns_fd = -1; + cleanup_close int mntns_fd = -1; + cleanup_close int fd = -1; long pid; char buf[12]; uid_t uid; gid_t gid; char path[PATH_MAX]; const char *const suffix = "/libpod/tmp/pause.pid"; - char *cwd = getcwd (NULL, 0); char uid_fmt[16]; char gid_fmt[16]; size_t len; + int r; + cwd = getcwd (NULL, 0); if (cwd == NULL) { - fprintf (stderr, "error getting current working directory: %s\n", strerror (errno)); + fprintf (stderr, "error getting current working directory: %m\n"); _exit (EXIT_FAILURE); } len = snprintf (path, PATH_MAX, "%s%s", xdg_runtime_dir, suffix); if (len >= PATH_MAX) { - fprintf (stderr, "invalid value for XDG_RUNTIME_DIR: %s", strerror (ENAMETOOLONG)); + errno = ENAMETOOLONG; + fprintf (stderr, "invalid value for XDG_RUNTIME_DIR: %m"); exit (EXIT_FAILURE); } fd = open (path, O_RDONLY); if (fd < 0) - { - free (cwd); - return; - } + return; r = TEMP_FAILURE_RETRY (read (fd, buf, sizeof (buf) - 1)); - close (fd); + if (r < 0) - { - free (cwd); - return; - } + return; buf[r] = '\0'; pid = strtol (buf, NULL, 10); if (pid == LONG_MAX) - { - free (cwd); - return; - } + return; uid = geteuid (); gid = getegid (); - sprintf (path, "/proc/%ld/ns/user", pid); - fd = open (path, O_RDONLY); - if (fd < 0 || setns (fd, 0) < 0) - { - free (cwd); - return; - } - close (fd); + userns_fd = open_namespace (pid, "user"); + if (userns_fd < 0) + return; - /* Errors here cannot be ignored as we already joined a ns. */ - sprintf (path, "/proc/%ld/ns/mnt", pid); - fd = open (path, O_RDONLY); - if (fd < 0) + mntns_fd = open_namespace (pid, "mnt"); + if (mntns_fd < 0) + return; + + if (setns (userns_fd, 0) < 0) + return; + + /* The user namespace was joined, after this point errors are + not recoverable anymore. */ + + if (setns (mntns_fd, 0) < 0) { - fprintf (stderr, "cannot open %s: %s", path, strerror (errno)); + fprintf (stderr, "cannot join mount namespace for %ld: %m", pid); exit (EXIT_FAILURE); } @@ -409,33 +435,24 @@ static void __attribute__((constructor)) init() setenv ("_CONTAINERS_ROOTLESS_UID", uid_fmt, 1); setenv ("_CONTAINERS_ROOTLESS_GID", gid_fmt, 1); - r = setns (fd, 0); - if (r < 0) - { - fprintf (stderr, "cannot join mount namespace for %ld: %s", pid, strerror (errno)); - exit (EXIT_FAILURE); - } - close (fd); - if (syscall_setresgid (0, 0, 0) < 0) { - fprintf (stderr, "cannot setresgid: %s\n", strerror (errno)); + fprintf (stderr, "cannot setresgid: %m\n"); _exit (EXIT_FAILURE); } if (syscall_setresuid (0, 0, 0) < 0) { - fprintf (stderr, "cannot setresuid: %s\n", strerror (errno)); + fprintf (stderr, "cannot setresuid: %m\n"); _exit (EXIT_FAILURE); } if (chdir (cwd) < 0) { - fprintf (stderr, "cannot chdir to %s: %s\n", cwd, strerror (errno)); + fprintf (stderr, "cannot chdir to %s: %m\n", cwd); _exit (EXIT_FAILURE); } - free (cwd); rootless_uid_init = uid; rootless_gid_init = gid; } @@ -534,7 +551,7 @@ create_pause_process (const char *pause_pid_file_path, char **argv) fd = mkstemp (tmp_file_path); if (fd < 0) { - fprintf (stderr, "error creating temporary file: %s\n", strerror (errno)); + fprintf (stderr, "error creating temporary file: %m\n"); kill (pid, SIGKILL); _exit (EXIT_FAILURE); } @@ -542,7 +559,7 @@ create_pause_process (const char *pause_pid_file_path, char **argv) r = TEMP_FAILURE_RETRY (write (fd, pid_str, strlen (pid_str))); if (r < 0) { - fprintf (stderr, "cannot write to file descriptor: %s\n", strerror (errno)); + fprintf (stderr, "cannot write to file descriptor: %m\n"); kill (pid, SIGKILL); _exit (EXIT_FAILURE); } @@ -560,7 +577,7 @@ create_pause_process (const char *pause_pid_file_path, char **argv) r = TEMP_FAILURE_RETRY (write (p[1], "0", 1)); if (r < 0) { - fprintf (stderr, "cannot write to pipe: %s\n", strerror (errno)); + fprintf (stderr, "cannot write to pipe: %m\n"); _exit (EXIT_FAILURE); } close (p[1]); @@ -595,22 +612,6 @@ create_pause_process (const char *pause_pid_file_path, char **argv) } } -static int -open_namespace (int pid_to_join, const char *ns_file) -{ - char ns_path[PATH_MAX]; - int ret; - - ret = snprintf (ns_path, PATH_MAX, "/proc/%d/ns/%s", pid_to_join, ns_file); - if (ret == PATH_MAX) - { - fprintf (stderr, "internal error: namespace path too long\n"); - return -1; - } - - return open (ns_path, O_CLOEXEC | O_RDONLY); -} - static void join_namespace_or_die (const char *name, int ns_fd) { @@ -624,18 +625,20 @@ join_namespace_or_die (const char *name, int ns_fd) int reexec_userns_join (int pid_to_join, char *pause_pid_file_path) { + cleanup_close int userns_fd = -1; + cleanup_close int mntns_fd = -1; + cleanup_free char *cwd = NULL; char uid[16]; char gid[16]; - char **argv; + cleanup_free char *argv0 = NULL; + cleanup_free char **argv = NULL; int pid; - int mnt_ns = -1; - int user_ns = -1; - char *cwd = getcwd (NULL, 0); sigset_t sigset, oldsigset; + cwd = getcwd (NULL, 0); if (cwd == NULL) { - fprintf (stderr, "error getting current working directory: %s\n", strerror (errno)); + fprintf (stderr, "error getting current working directory: %m\n"); _exit (EXIT_FAILURE); } @@ -645,32 +648,27 @@ reexec_userns_join (int pid_to_join, char *pause_pid_file_path) argv = get_cmd_line_args (); if (argv == NULL) { - fprintf (stderr, "cannot read argv: %s\n", strerror (errno)); + fprintf (stderr, "cannot read argv: %m\n"); _exit (EXIT_FAILURE); } - user_ns = open_namespace (pid_to_join, "user"); - if (user_ns < 0) - return user_ns; - mnt_ns = open_namespace (pid_to_join, "mnt"); - if (mnt_ns < 0) - { - close (user_ns); - return mnt_ns; - } + argv0 = argv[0]; + + userns_fd = open_namespace (pid_to_join, "user"); + if (userns_fd < 0) + return userns_fd; + mntns_fd = open_namespace (pid_to_join, "mnt"); + if (mntns_fd < 0) + return mntns_fd; pid = fork (); if (pid < 0) - fprintf (stderr, "cannot fork: %s\n", strerror (errno)); + fprintf (stderr, "cannot fork: %m\n"); if (pid) { int f; - /* We passed down these fds, close them. */ - close (user_ns); - close (mnt_ns); - for (f = 3; f <= open_files_max_fd; f++) if (is_fd_inherited (f)) close (f); @@ -686,22 +684,22 @@ reexec_userns_join (int pid_to_join, char *pause_pid_file_path) if (sigfillset (&sigset) < 0) { - fprintf (stderr, "cannot fill sigset: %s\n", strerror (errno)); + fprintf (stderr, "cannot fill sigset: %m\n"); _exit (EXIT_FAILURE); } if (sigdelset (&sigset, SIGCHLD) < 0) { - fprintf (stderr, "cannot sigdelset(SIGCHLD): %s\n", strerror (errno)); + fprintf (stderr, "cannot sigdelset(SIGCHLD): %m\n"); _exit (EXIT_FAILURE); } if (sigdelset (&sigset, SIGTERM) < 0) { - fprintf (stderr, "cannot sigdelset(SIGTERM): %s\n", strerror (errno)); + fprintf (stderr, "cannot sigdelset(SIGTERM): %m\n"); _exit (EXIT_FAILURE); } if (sigprocmask (SIG_BLOCK, &sigset, &oldsigset) < 0) { - fprintf (stderr, "cannot block signals: %s\n", strerror (errno)); + fprintf (stderr, "cannot block signals: %m\n"); _exit (EXIT_FAILURE); } @@ -722,33 +720,30 @@ reexec_userns_join (int pid_to_join, char *pause_pid_file_path) if (prctl (PR_SET_PDEATHSIG, SIGTERM, 0, 0, 0) < 0) { - fprintf (stderr, "cannot prctl(PR_SET_PDEATHSIG): %s\n", strerror (errno)); + fprintf (stderr, "cannot prctl(PR_SET_PDEATHSIG): %m\n"); _exit (EXIT_FAILURE); } - join_namespace_or_die ("user", user_ns); - join_namespace_or_die ("mnt", mnt_ns); - close (user_ns); - close (mnt_ns); + join_namespace_or_die ("user", userns_fd); + join_namespace_or_die ("mnt", mntns_fd); if (syscall_setresgid (0, 0, 0) < 0) { - fprintf (stderr, "cannot setresgid: %s\n", strerror (errno)); + fprintf (stderr, "cannot setresgid: %m\n"); _exit (EXIT_FAILURE); } if (syscall_setresuid (0, 0, 0) < 0) { - fprintf (stderr, "cannot setresuid: %s\n", strerror (errno)); + fprintf (stderr, "cannot setresuid: %m\n"); _exit (EXIT_FAILURE); } if (chdir (cwd) < 0) { - fprintf (stderr, "cannot chdir to %s: %s\n", cwd, strerror (errno)); + fprintf (stderr, "cannot chdir to %s: %m\n", cwd); _exit (EXIT_FAILURE); } - free (cwd); if (pause_pid_file_path && pause_pid_file_path[0] != '\0') { @@ -757,7 +752,7 @@ reexec_userns_join (int pid_to_join, char *pause_pid_file_path) } if (sigprocmask (SIG_SETMASK, &oldsigset, NULL) < 0) { - fprintf (stderr, "cannot block signals: %s\n", strerror (errno)); + fprintf (stderr, "cannot block signals: %m\n"); _exit (EXIT_FAILURE); } @@ -789,7 +784,7 @@ static int copy_file_to_fd (const char *file_to_read, int outfd) { char buf[512]; - int fd; + cleanup_close int fd = -1; fd = open (file_to_read, O_RDONLY); if (fd < 0) @@ -801,10 +796,7 @@ copy_file_to_fd (const char *file_to_read, int outfd) r = TEMP_FAILURE_RETRY (read (fd, buf, sizeof buf)); if (r < 0) - { - close (fd); - return r; - } + return r; if (r == 0) break; @@ -813,43 +805,40 @@ copy_file_to_fd (const char *file_to_read, int outfd) { w = TEMP_FAILURE_RETRY (write (outfd, &buf[t], r - t)); if (w < 0) - { - close (fd); - return w; - } + return w; t += w; } } - close (fd); return 0; } int reexec_in_user_namespace (int ready, char *pause_pid_file_path, char *file_to_read, int outputfd) { + cleanup_free char **argv = NULL; + cleanup_free char *argv0 = NULL; + cleanup_free char *cwd = NULL; + sigset_t sigset, oldsigset; int ret; pid_t pid; char b; - char **argv; char uid[16]; char gid[16]; - char *cwd = getcwd (NULL, 0); - sigset_t sigset, oldsigset; + cwd = getcwd (NULL, 0); if (cwd == NULL) { - fprintf (stderr, "error getting current working directory: %s\n", strerror (errno)); + fprintf (stderr, "error getting current working directory: %m\n"); _exit (EXIT_FAILURE); } - sprintf (uid, "%d", geteuid ()); sprintf (gid, "%d", getegid ()); pid = syscall_clone (CLONE_NEWUSER|CLONE_NEWNS|SIGCHLD, NULL); if (pid < 0) { - fprintf (stderr, "cannot clone: %s\n", strerror (errno)); + fprintf (stderr, "cannot clone: %m\n"); check_proc_sys_userns_file (_max_user_namespaces); check_proc_sys_userns_file (_unprivileged_user_namespaces); } @@ -877,32 +866,34 @@ reexec_in_user_namespace (int ready, char *pause_pid_file_path, char *file_to_re if (sigfillset (&sigset) < 0) { - fprintf (stderr, "cannot fill sigset: %s\n", strerror (errno)); + fprintf (stderr, "cannot fill sigset: %m\n"); _exit (EXIT_FAILURE); } if (sigdelset (&sigset, SIGCHLD) < 0) { - fprintf (stderr, "cannot sigdelset(SIGCHLD): %s\n", strerror (errno)); + fprintf (stderr, "cannot sigdelset(SIGCHLD): %m\n"); _exit (EXIT_FAILURE); } if (sigdelset (&sigset, SIGTERM) < 0) { - fprintf (stderr, "cannot sigdelset(SIGTERM): %s\n", strerror (errno)); + fprintf (stderr, "cannot sigdelset(SIGTERM): %m\n"); _exit (EXIT_FAILURE); } if (sigprocmask (SIG_BLOCK, &sigset, &oldsigset) < 0) { - fprintf (stderr, "cannot block signals: %s\n", strerror (errno)); + fprintf (stderr, "cannot block signals: %m\n"); _exit (EXIT_FAILURE); } argv = get_cmd_line_args (); if (argv == NULL) { - fprintf (stderr, "cannot read argv: %s\n", strerror (errno)); + fprintf (stderr, "cannot read argv: %m\n"); _exit (EXIT_FAILURE); } + argv0 = argv[0]; + if (do_socket_activation) { char s[32]; @@ -921,7 +912,7 @@ reexec_in_user_namespace (int ready, char *pause_pid_file_path, char *file_to_re ret = TEMP_FAILURE_RETRY (read (ready, &b, 1)); if (ret < 0) { - fprintf (stderr, "cannot read from sync pipe: %s\n", strerror (errno)); + fprintf (stderr, "cannot read from sync pipe: %m\n"); _exit (EXIT_FAILURE); } if (ret != 1 || b != '0') @@ -929,25 +920,24 @@ reexec_in_user_namespace (int ready, char *pause_pid_file_path, char *file_to_re if (syscall_setresgid (0, 0, 0) < 0) { - fprintf (stderr, "cannot setresgid: %s\n", strerror (errno)); + fprintf (stderr, "cannot setresgid: %m\n"); TEMP_FAILURE_RETRY (write (ready, "1", 1)); _exit (EXIT_FAILURE); } if (syscall_setresuid (0, 0, 0) < 0) { - fprintf (stderr, "cannot setresuid: %s\n", strerror (errno)); + fprintf (stderr, "cannot setresuid: %m\n"); TEMP_FAILURE_RETRY (write (ready, "1", 1)); _exit (EXIT_FAILURE); } if (chdir (cwd) < 0) { - fprintf (stderr, "cannot chdir to %s: %s\n", cwd, strerror (errno)); + fprintf (stderr, "cannot chdir to %s: %m\n", cwd); TEMP_FAILURE_RETRY (write (ready, "1", 1)); _exit (EXIT_FAILURE); } - free (cwd); if (pause_pid_file_path && pause_pid_file_path[0] != '\0') { @@ -961,14 +951,14 @@ reexec_in_user_namespace (int ready, char *pause_pid_file_path, char *file_to_re ret = TEMP_FAILURE_RETRY (write (ready, "0", 1)); if (ret < 0) { - fprintf (stderr, "cannot write to ready pipe: %s\n", strerror (errno)); - _exit (EXIT_FAILURE); + fprintf (stderr, "cannot write to ready pipe: %m\n"); + _exit (EXIT_FAILURE); } close (ready); if (sigprocmask (SIG_SETMASK, &oldsigset, NULL) < 0) { - fprintf (stderr, "cannot block signals: %s\n", strerror (errno)); + fprintf (stderr, "cannot block signals: %m\n"); _exit (EXIT_FAILURE); } |