1 files changed, 46 insertions, 134 deletions

diff --git a/src/firejail/util.c b/src/firejail/util.c
index 094a68c60..55dcdc246 100644
--- a/src/firejail/util.c
+++ b/src/firejail/util.c
@@ -20,8 +20,6 @@
 #define _XOPEN_SOURCE 500
 #include "firejail.h"
 #include "../include/gcov_wrapper.h"
-#include <ftw.h>
-#include <sys/stat.h>
 #include <sys/mount.h>
 #include <syslog.h>
 #include <errno.h>
@@ -32,9 +30,6 @@
 #include <sys/wait.h>
 #include <limits.h>
 
-#include <string.h>
-#include <ctype.h>
-
 #include <fcntl.h>
 #ifndef O_PATH
 #define O_PATH 010000000
@@ -459,31 +454,21 @@ int is_dir(const char *fname) {
         if (*fname == '\0')
                 return 0;
 
-        int called_as_root = 0;
-        if (geteuid() == 0)
-                called_as_root = 1;
-
-        if (called_as_root)
-                EUID_USER();
-
         // if fname doesn't end in '/', add one
         int rv;
         struct stat s;
         if (fname[strlen(fname) - 1] == '/')
-                rv = stat(fname, &s);
+                rv = stat_as_user(fname, &s);
         else {
                 char *tmp;
                 if (asprintf(&tmp, "%s/", fname) == -1) {
                         fprintf(stderr, "Error: cannot allocate memory, %s:%d\n", __FILE__, __LINE__);
                         errExit("asprintf");
                 }
-                rv = stat(tmp, &s);
+                rv = stat_as_user(tmp, &s);
                 free(tmp);
         }
 
-        if (called_as_root)
-                EUID_ROOT();
-
         if (rv == -1)
                 return 0;
 
@@ -499,13 +484,6 @@ int is_link(const char *fname) {
         if (*fname == '\0')
                 return 0;
 
-        int called_as_root = 0;
-        if (geteuid() == 0)
-                called_as_root = 1;
-
-        if (called_as_root)
-                EUID_USER();
-
         // remove trailing '/' if any
         char *tmp = strdup(fname);
         if (!tmp)
@@ -513,12 +491,9 @@ int is_link(const char *fname) {
         trim_trailing_slash_or_dot(tmp);
 
         char c;
-        ssize_t rv = readlink(tmp, &c, 1);
+        ssize_t rv = readlink_as_user(tmp, &c, 1);
         free(tmp);
 
-        if (called_as_root)
-                EUID_ROOT();
-
         return (rv != -1);
 }
 
@@ -540,6 +515,24 @@ char *realpath_as_user(const char *fname) {
         return rv;
 }
 
+ssize_t readlink_as_user(const char *fname, char *buf, size_t sz) {
+        assert(fname && buf && sz);
+
+        int called_as_root = 0;
+        if (geteuid() == 0)
+                called_as_root = 1;
+
+        if (called_as_root)
+                EUID_USER();
+
+        ssize_t rv = readlink(fname, buf, sz);
+
+        if (called_as_root)
+                EUID_ROOT();
+
+        return rv;
+}
+
 int stat_as_user(const char *fname, struct stat *s) {
         assert(fname);
 
@@ -974,12 +967,9 @@ uid_t pid_get_uid(pid_t pid) {
 }
 
 
-
-
-uid_t get_group_id(const char *group) {
-        // find tty group id
+gid_t get_group_id(const char *groupname) {
         gid_t gid = 0;
-        struct group *g = getgrnam(group);
+        struct group *g = getgrnam(groupname);
         if (g)
                 gid = g->gr_gid;
 
@@ -987,86 +977,6 @@ uid_t get_group_id(const char *group) {
 }
 
 
-static int remove_callback(const char *fpath, const struct stat *sb, int typeflag, struct FTW *ftwbuf) {
-        (void) sb;
-        (void) typeflag;
-        (void) ftwbuf;
-        assert(fpath);
-
-        if (strcmp(fpath, ".") == 0)
-                return 0;
-
-        if (remove(fpath)) {    // removes the link not the actual file
-                perror("remove");
-                fprintf(stderr, "Error: cannot remove file from user .firejail directory: %s\n", fpath);
-                exit(1);
-        }
-
-        return 0;
-}
-
-
-int remove_overlay_directory(void) {
-        EUID_ASSERT();
-        sleep(1);
-
-        char *path;
-        if (asprintf(&path, "%s/.firejail", cfg.homedir) == -1)
-                errExit("asprintf");
-
-        if (access(path, F_OK) == 0) {
-                pid_t child = fork();
-                if (child < 0)
-                        errExit("fork");
-                if (child == 0) {
-                        // open ~/.firejail
-                        int fd = safer_openat(-1, path, O_PATH|O_NOFOLLOW|O_CLOEXEC);
-                        if (fd == -1) {
-                                fprintf(stderr, "Error: cannot open %s\n", path);
-                                exit(1);
-                        }
-                        struct stat s;
-                        if (fstat(fd, &s) == -1)
-                                errExit("fstat");
-                        if (!S_ISDIR(s.st_mode)) {
-                                if (S_ISLNK(s.st_mode))
-                                        fprintf(stderr, "Error: %s is a symbolic link\n", path);
-                                else
-                                        fprintf(stderr, "Error: %s is not a directory\n", path);
-                                exit(1);
-                        }
-                        if (s.st_uid != getuid()) {
-                                fprintf(stderr, "Error: %s is not owned by the current user\n", path);
-                                exit(1);
-                        }
-                        // chdir to ~/.firejail
-                        if (fchdir(fd) == -1)
-                                errExit("fchdir");
-                        close(fd);
-
-                        EUID_ROOT();
-                        // FTW_PHYS - do not follow symbolic links
-                        if (nftw(".", remove_callback, 64, FTW_DEPTH | FTW_PHYS) == -1)
-                                errExit("nftw");
-
-                        EUID_USER();
-                        // remove ~/.firejail
-                        if (rmdir(path) == -1)
-                                errExit("rmdir");
-
-                        __gcov_flush();
-
-                        _exit(0);
-                }
-                // wait for the child to finish
-                waitpid(child, NULL, 0);
-                // check if ~/.firejail was deleted
-                if (access(path, F_OK) == 0)
-                        return 1;
-        }
-        return 0;
-}
-
 // flush stdin if it is connected to a tty and has input
 void flush_stdin(void) {
         if (!isatty(STDIN_FILENO))
@@ -1095,31 +1005,33 @@ int create_empty_dir_as_user(const char *dir, mode_t mode) {
         assert(dir);
         mode &= 07777;
 
-        if (access(dir, F_OK) != 0) {
+        if (access(dir, F_OK) == 0)
+                return 0;
+
+        pid_t child = fork();
+        if (child < 0)
+                errExit("fork");
+        if (child == 0) {
+                // drop privileges
+                drop_privs(0);
+
                 if (arg_debug)
                         printf("Creating empty %s directory\n", dir);
-                pid_t child = fork();
-                if (child < 0)
-                        errExit("fork");
-                if (child == 0) {
-                        // drop privileges
-                        drop_privs(0);
-
-                        if (mkdir(dir, mode) == 0) {
-                                int err = chmod(dir, mode);
-                                (void) err;
-                        }
-                        else if (arg_debug)
-                                printf("Directory %s not created: %s\n", dir, strerror(errno));
+                if (mkdir(dir, mode) == 0) {
+                        int err = chmod(dir, mode);
+                        (void) err;
+                }
+                else if (arg_debug)
+                        printf("Directory %s not created: %s\n", dir, strerror(errno));
 
-                        __gcov_flush();
+                __gcov_flush();
 
-                        _exit(0);
-                }
-                waitpid(child, NULL, 0);
-                if (access(dir, F_OK) == 0)
-                        return 1;
+                _exit(0);
         }
+        waitpid(child, NULL, 0);
+
+        if (access(dir, F_OK) == 0)
+                        return 1;
         return 0;
 }
 
@@ -1509,7 +1421,7 @@ static int has_link(const char *dir) {
 void check_homedir(const char *dir) {
         assert(dir);
         if (dir[0] != '/') {
-                fprintf(stderr, "Error: invalid user directory \"%s\"\n", cfg.homedir);
+                fprintf(stderr, "Error: invalid user directory \"%s\"\n", dir);
                 exit(1);
         }
         // symlinks are rejected in many places