fcaps: clear the same personality flags as suid when fcaps are used

If a process increases permissions using fcaps all of the dangerous personality flags which are cleared for suid apps should also be cleared. Thus programs given priviledge with fcaps will continue to have address space randomization enabled even if the parent tried to disable it to make it easier to attack. Signed-off-by: Eric Paris <[email protected]> Reviewed-by: Serge Hallyn <[email protected]> Signed-off-by: James Morris <[email protected]>
zuai · Apr 18, 2012 · d52fc5d · d52fc5d
1 parent 09c79b6
commit d52fc5d
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/security/commoncap.c b/security/commoncap.c
@@ -505,6 +505,11 @@ int cap_bprm_set_creds(struct linux_binprm *bprm)
 	}
 skip:
 
+	/* if we have fs caps, clear dangerous personality flags */
+	if (!cap_issubset(new->cap_permitted, old->cap_permitted))
+		bprm->per_clear |= PER_CLEAR_ON_SETID;
+
+
 	/* Don't let someone trace a set[ug]id/setpcap binary with the revised
 	 * credentials unless they have the appropriate permit
 	 */