diff options
Diffstat (limited to 'pkg/rootless/rootless_linux.c')
| -rw-r--r-- | pkg/rootless/rootless_linux.c | 203 |
1 files changed, 97 insertions, 106 deletions
diff --git a/pkg/rootless/rootless_linux.c b/pkg/rootless/rootless_linux.c index 6ce4b1e29..b60aea855 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; @@ -114,8 +141,8 @@ 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; @@ -134,10 +161,7 @@ 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; @@ -148,30 +172,21 @@ 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; @@ -181,15 +196,19 @@ 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; @@ -199,12 +218,10 @@ 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++) { @@ -229,8 +246,6 @@ can_use_shortcut () } } - free (argv[0]); - free (argv); return ret; } @@ -250,8 +265,7 @@ 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]) @@ -299,7 +313,6 @@ static void __attribute__((constructor)) init() FD_SET (fd % FD_SETSIZE, &(open_files_set[fd / FD_SETSIZE])); } - closedir (d); } listen_pid = getenv("LISTEN_PID"); @@ -327,19 +340,22 @@ 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)); @@ -355,45 +371,40 @@ static void __attribute__((constructor)) init() 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 (path, O_RDONLY); + 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 (path, O_RDONLY); + 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: %s", pid, strerror (errno)); exit (EXIT_FAILURE); } @@ -404,14 +415,6 @@ 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)); @@ -430,7 +433,6 @@ static void __attribute__((constructor)) init() _exit (EXIT_FAILURE); } - free (cwd); rootless_uid_init = uid; rootless_gid_init = gid; } @@ -619,15 +621,17 @@ 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)); @@ -644,15 +648,14 @@ reexec_userns_join (int pid_to_join, char *pause_pid_file_path) _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) @@ -662,10 +665,6 @@ reexec_userns_join (int pid_to_join, char *pause_pid_file_path) { 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); @@ -721,10 +720,8 @@ reexec_userns_join (int pid_to_join, char *pause_pid_file_path) _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) { @@ -743,7 +740,6 @@ reexec_userns_join (int pid_to_join, char *pause_pid_file_path) fprintf (stderr, "cannot chdir to %s: %s\n", cwd, strerror (errno)); _exit (EXIT_FAILURE); } - free (cwd); if (pause_pid_file_path && pause_pid_file_path[0] != '\0') { @@ -784,7 +780,7 @@ 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) @@ -796,10 +792,7 @@ 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; @@ -808,36 +801,33 @@ 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)); _exit (EXIT_FAILURE); } - sprintf (uid, "%d", geteuid ()); sprintf (gid, "%d", getegid ()); @@ -898,6 +888,8 @@ reexec_in_user_namespace (int ready, char *pause_pid_file_path, char *file_to_re _exit (EXIT_FAILURE); } + argv0 = argv[0]; + if (do_socket_activation) { char s[32]; @@ -942,7 +934,6 @@ reexec_in_user_namespace (int ready, char *pause_pid_file_path, char *file_to_re TEMP_FAILURE_RETRY (write (ready, "1", 1)); _exit (EXIT_FAILURE); } - free (cwd); if (pause_pid_file_path && pause_pid_file_path[0] != '\0') { @@ -956,8 +947,8 @@ 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: %s\n", strerror (errno)); + _exit (EXIT_FAILURE); } close (ready); |