1 files changed, 32 insertions, 15 deletions

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 00ad46e166f6..04b8e1082c9a 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -2318,6 +2318,7 @@ static int check_nnp_nosuid(const struct linux_binprm *bprm,
         int nnp = (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS);
         int nosuid = !mnt_may_suid(bprm->file->f_path.mnt);
         int rc;
+        u32 av;
 
         if (!nnp && !nosuid)
                 return 0; /* neither NNP nor nosuid */
@@ -2326,24 +2327,40 @@ static int check_nnp_nosuid(const struct linux_binprm *bprm,
                 return 0; /* No change in credentials */
 
         /*
-         * The only transitions we permit under NNP or nosuid
-         * are transitions to bounded SIDs, i.e. SIDs that are
-         * guaranteed to only be allowed a subset of the permissions
-         * of the current SID.
+         * If the policy enables the nnp_nosuid_transition policy capability,
+         * then we permit transitions under NNP or nosuid if the
+         * policy allows the corresponding permission between
+         * the old and new contexts.
          */
-        rc = security_bounded_transition(old_tsec->sid, new_tsec->sid);
-        if (rc) {
-                /*
-                 * On failure, preserve the errno values for NNP vs nosuid.
-                 * NNP:  Operation not permitted for caller.
-                 * nosuid:  Permission denied to file.
-                 */
+        if (selinux_policycap_nnp_nosuid_transition) {
+                av = 0;
                 if (nnp)
-                        return -EPERM;
-                else
-                        return -EACCES;
+                        av |= PROCESS2__NNP_TRANSITION;
+                if (nosuid)
+                        av |= PROCESS2__NOSUID_TRANSITION;
+                rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
+                                  SECCLASS_PROCESS2, av, NULL);
+                if (!rc)
+                        return 0;
         }
-        return 0;
+
+        /*
+         * We also permit NNP or nosuid transitions to bounded SIDs,
+         * i.e. SIDs that are guaranteed to only be allowed a subset
+         * of the permissions of the current SID.
+         */
+        rc = security_bounded_transition(old_tsec->sid, new_tsec->sid);
+        if (!rc)
+                return 0;
+
+        /*
+         * On failure, preserve the errno values for NNP vs nosuid.
+         * NNP:  Operation not permitted for caller.
+         * nosuid:  Permission denied to file.
+         */
+        if (nnp)
+                return -EPERM;
+        return -EACCES;
 }
 
 static int selinux_bprm_set_creds(struct linux_binprm *bprm)