3 files changed, 18 insertions, 3 deletions

diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c
index 6327685c101e..18c88d06e881 100644
--- a/security/apparmor/domain.c
+++ b/security/apparmor/domain.c
@@ -360,6 +360,10 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm)
         if (bprm->cred_prepared)
                 return 0;
 
+        /* XXX: no_new_privs is not usable with AppArmor yet */
+        if (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS)
+                return -EPERM;
+
         cxt = bprm->cred->security;
         BUG_ON(!cxt);
 
diff --git a/security/commoncap.c b/security/commoncap.c
index 0cf4b53480a7..edd3918fac02 100644
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -506,14 +506,17 @@ int cap_bprm_set_creds(struct linux_binprm *bprm)
 skip:
 
         /* Don't let someone trace a set[ug]id/setpcap binary with the revised
-         * credentials unless they have the appropriate permit
+         * credentials unless they have the appropriate permit.
+         *
+         * In addition, if NO_NEW_PRIVS, then ensure we get no new privs.
          */
         if ((new->euid != old->uid ||
              new->egid != old->gid ||
              !cap_issubset(new->cap_permitted, old->cap_permitted)) &&
             bprm->unsafe & ~LSM_UNSAFE_PTRACE_CAP) {
                 /* downgrade; they get no more than they had, and maybe less */
-                if (!capable(CAP_SETUID)) {
+                if (!capable(CAP_SETUID) ||
+                    (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS)) {
                         new->euid = new->uid;
                         new->egid = new->gid;
                 }
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index d85b793c9321..0b06685787b9 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -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) {