Add PR_{GET,SET}_NO_NEW_PRIVS to prevent execve from granting privs
[linux-3.10.git] / security / selinux / hooks.c
index d85b793..0b06685 100644 (file)
@@ -2016,6 +2016,13 @@ static int selinux_bprm_set_creds(struct linux_binprm *bprm)
                new_tsec->sid = old_tsec->exec_sid;
                /* Reset exec SID on execve. */
                new_tsec->exec_sid = 0;
+
+               /*
+                * Minimize confusion: if no_new_privs and a transition is
+                * explicitly requested, then fail the exec.
+                */
+               if (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS)
+                       return -EPERM;
        } else {
                /* Check for a default transition on this program. */
                rc = security_transition_sid(old_tsec->sid, isec->sid,
@@ -2029,7 +2036,8 @@ static int selinux_bprm_set_creds(struct linux_binprm *bprm)
        ad.selinux_audit_data = &sad;
        ad.u.path = bprm->file->f_path;
 
-       if (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)
+       if ((bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID) ||
+           (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS))
                new_tsec->sid = old_tsec->sid;
 
        if (new_tsec->sid == old_tsec->sid) {