tree-wide: use ASSERT_PTR more

[thirdparty/systemd.git] / src / shared / exec-util.c

diff --git a/src/shared/exec-util.c b/src/shared/exec-util.c
index dc4214d162b458dcdf0234b25713ef21e3870084..19ddf0498625d72bd973a68ee4af3475b86c8bfe 100644 (file)
--- a/src/shared/exec-util.c
+++ b/src/shared/exec-util.c
@@ -50,7 +50,7 @@ static int do_spawn(const char *path, char *argv[], int stdout_fd, pid_t *pid, b
                 char *_argv[2];
 
                 if (stdout_fd >= 0) {
-                        r = rearrange_stdio(STDIN_FILENO, stdout_fd, STDERR_FILENO);
+                        r = rearrange_stdio(STDIN_FILENO, TAKE_FD(stdout_fd), STDERR_FILENO);
                         if (r < 0)
                                 _exit(EXIT_FAILURE);
                 }
@@ -91,7 +91,6 @@ static int do_execute(
 
         _cleanup_hashmap_free_free_ Hashmap *pids = NULL;
         _cleanup_strv_free_ char **paths = NULL;
-        char **path, **e;
         int r;
         bool parallel_execution;
 
@@ -254,7 +253,7 @@ int execute_directories(
 }
 
 static int gather_environment_generate(int fd, void *arg) {
-        char ***env = arg, **x, **y;
+        char ***env = ASSERT_PTR(arg);
         _cleanup_fclose_ FILE *f = NULL;
         _cleanup_strv_free_ char **new = NULL;
         int r;
@@ -265,8 +264,6 @@ static int gather_environment_generate(int fd, void *arg) {
          * fd is always consumed, even on error.
          */
 
-        assert(env);
-
         f = fdopen(fd, "r");
         if (!f) {
                 safe_close(fd);
@@ -296,13 +293,11 @@ static int gather_environment_generate(int fd, void *arg) {
 
 static int gather_environment_collect(int fd, void *arg) {
         _cleanup_fclose_ FILE *f = NULL;
-        char ***env = arg;
+        char ***env = ASSERT_PTR(arg);
         int r;
 
         /* Write out a series of env=cescape(VAR=value) assignments to fd. */
 
-        assert(env);
-
         f = fdopen(fd, "w");
         if (!f) {
                 safe_close(fd);
@@ -322,13 +317,11 @@ static int gather_environment_collect(int fd, void *arg) {
 
 static int gather_environment_consume(int fd, void *arg) {
         _cleanup_fclose_ FILE *f = NULL;
-        char ***env = arg;
+        char ***env = ASSERT_PTR(arg);
         int r = 0;
 
         /* Read a series of env=cescape(VAR=value) assignments from fd into env. */
 
-        assert(env);
-
         f = fdopen(fd, "r");
         if (!f) {
                 safe_close(fd);
@@ -369,7 +362,6 @@ static int gather_environment_consume(int fd, void *arg) {
 
 int exec_command_flags_from_strv(char **ex_opts, ExecCommandFlags *flags) {
         ExecCommandFlags ex_flag, ret_flags = 0;
-        char **opt;
 
         assert(flags);
 
@@ -448,31 +440,17 @@ ExecCommandFlags exec_command_flags_from_string(const char *s) {
                 return 1 << idx;
 }
 
-_noreturn_ void freeze(void) {
-        log_close();
-
-        /* Make sure nobody waits for us on a socket anymore */
-        (void) close_all_fds_full(NULL, 0, false);
-
-        sync();
-
-        /* Let's not freeze right away, but keep reaping zombies. */
-        for (;;) {
-                int r;
-                siginfo_t si = {};
-
-                r = waitid(P_ALL, 0, &si, WEXITED);
-                if (r < 0 && errno != EINTR)
-                        break;
-        }
+int fexecve_or_execve(int executable_fd, const char *executable, char *const argv[], char *const envp[]) {
+        /* Refuse invalid fds, regardless if fexecve() use is enabled or not */
+        if (executable_fd < 0)
+                return -EBADF;
 
-        /* waitid() failed with an unexpected error, things are really borked. Freeze now! */
-        for (;;)
-                pause();
-}
+        /* Block any attempts on exploiting Linux' liberal argv[] handling, i.e. CVE-2021-4034 and suchlike */
+        if (isempty(executable) || strv_isempty(argv))
+                return -EINVAL;
 
-int fexecve_or_execve(int executable_fd, const char *executable, char *const argv[], char *const envp[]) {
 #if ENABLE_FEXECVE
+
         execveat(executable_fd, "", argv, envp, AT_EMPTY_PATH);
 
         if (IN_SET(errno, ENOSYS, ENOENT) || ERRNO_IS_PRIVILEGE(errno))
@@ -494,7 +472,7 @@ int fexecve_or_execve(int executable_fd, const char *executable, char *const arg
         return -errno;
 }
 
-int fork_agent(const char *name, int except[], size_t n_except, pid_t *ret_pid, const char *path, ...) {
+int fork_agent(const char *name, const int except[], size_t n_except, pid_t *ret_pid, const char *path, ...) {
         bool stdout_is_tty, stderr_is_tty;
         size_t n, i;
         va_list ap;
@@ -529,7 +507,7 @@ int fork_agent(const char *name, int except[], size_t n_except, pid_t *ret_pid,
                  * stdin around. */
                 fd = open("/dev/tty", O_WRONLY);
                 if (fd < 0) {
-                        if (errno != -ENXIO) {
+                        if (errno != ENXIO) {
                                 log_error_errno(errno, "Failed to open /dev/tty: %m");
                                 _exit(EXIT_FAILURE);
                         }