Add support for SELinux labeling

Running `firejail --noprofile --private-bin=bash,ls ls -1Za /usr/bin`
shows that the SELinux labels are not correct:
```
user_u:object_r:user_tmpfs_t:s0 .
     system_u:object_r:usr_t:s0 ..
user_u:object_r:user_tmpfs_t:s0 bash
user_u:object_r:user_tmpfs_t:s0 ls
```

After fixing this:
```
       system_u:object_r:bin_t:s0 .
       system_u:object_r:usr_t:s0 ..
system_u:object_r:shell_exec_t:s0 bash
       system_u:object_r:bin_t:s0 ls
```

Most copied files and created directories should now have correct
labels (bind mounted objects keep their labels). This is useful to
avoid having to change the SELinux rules when using Firejail.

1 files changed, 4 insertions, 0 deletions

diff --git a/src/firejail/restrict_users.c b/src/firejail/restrict_users.c
index b51172219..5ebb0e9ec 100644
--- a/src/firejail/restrict_users.c
+++ b/src/firejail/restrict_users.c
@@ -97,6 +97,7 @@ static void sanitize_home(void) {
         // mount tmpfs in the new home
         if (mount("tmpfs", "/home", "tmpfs", MS_NOSUID | MS_NODEV | MS_STRICTATIME,  "mode=755,gid=0") < 0)
                 errExit("mount tmpfs");
+        selinux_relabel_path("/home", "/home");
         fs_logger("tmpfs /home");
 
         // create user home directory
@@ -105,6 +106,7 @@ static void sanitize_home(void) {
                         errExit("mkpath");
                 if (mkdir(cfg.homedir, 0755) == -1)
                         errExit("mkdir");
+                selinux_relabel_path(cfg.homedir, cfg.homedir);
         }
         fs_logger2("mkdir", cfg.homedir);
 
@@ -152,11 +154,13 @@ static void sanitize_run(void) {
         // mount tmpfs on /run/user
         if (mount("tmpfs", "/run/user", "tmpfs", MS_NOSUID | MS_NODEV | MS_STRICTATIME,  "mode=755,gid=0") < 0)
                 errExit("mount tmpfs");
+        selinux_relabel_path("/run/user", "/run/user");
         fs_logger("tmpfs /run/user");
 
         // create new user directory
         if (mkdir(runuser, 0700) == -1)
                 errExit("mkdir");
+        selinux_relabel_path(runuser, runuser);
         fs_logger2("mkdir", runuser);
 
         // set mode and ownership