---
 security/commoncap.c |   18 +++++++++++-------
 1 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/security/commoncap.c b/security/commoncap.c
index 927fe93..cf6e2b0 100644
--- a/security/commoncap.c
+++ b/security/commoncap.c

@@ -505,6 +505,12 @@ static void handle_privileged_root(struct linux_binprm *bprm, bool has_cap,
                *effective = true;
 }

+#define __cap_gained(field, target, source) \
+       !cap_issubset(target->cap_##field, source->cap_##field)
+#define __cap_grew(target, source, cred) \
+       !cap_issubset(cred->cap_##target, cred->cap_##source)
+#define __cap_full(field, cred) \
+       cap_issubset(CAP_FULL_SET, cred->cap_##field)

 /**
  * cap_bprm_set_creds - Set up the proposed credentials for execve().
  * @bprm: The execution parameters, including the proposed creds

@@ -533,10 +539,9 @@ int cap_bprm_set_creds(struct linux_binprm *bprm)
        handle_privileged_root(bprm, has_cap, &effective, root_uid);

        /* if we have fs caps, clear dangerous personality flags */
-       if (!cap_issubset(new->cap_permitted, old->cap_permitted))
+       if (__cap_gained(permitted, new, old))
                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.
         *

@@ -544,8 +549,7 @@ int cap_bprm_set_creds(struct linux_binprm *bprm)
         */
        is_setid = !uid_eq(new->euid, old->uid) || !gid_eq(new->egid, old->gid);

-       if ((is_setid ||
-            !cap_issubset(new->cap_permitted, old->cap_permitted)) &&
+       if ((is_setid || __cap_gained(permitted, new, old)) &&
            ((bprm->unsafe & ~LSM_UNSAFE_PTRACE) ||
             !ptracer_capable(current, new->user_ns))) {
                /* downgrade; they get no more than they had, and maybe less */

@@ -595,8 +599,8 @@ int cap_bprm_set_creds(struct linux_binprm *bprm)
         * Number 1 above might fail if you don't have a full bset, but I think
         * that is interesting information to audit.
         */
-       if (!cap_issubset(new->cap_effective, new->cap_ambient)) {
-               if (!cap_issubset(CAP_FULL_SET, new->cap_effective) ||
+       if (__cap_grew(effective, ambient, new)) {
+               if (!__cap_full(effective, new) ||
                    !uid_eq(new->euid, root_uid) || !uid_eq(new->uid, root_uid) ||
                    issecure(SECURE_NOROOT)) {
                        ret = audit_log_bprm_fcaps(bprm, new, old);

@@ -616,7 +620,7 @@ int cap_bprm_set_creds(struct linux_binprm *bprm)
                bprm->cap_elevated = 1;
        } else if (!uid_eq(new->uid, root_uid)) {
                if (effective ||
-                   !cap_issubset(new->cap_permitted, new->cap_ambient))
+                   __cap_grew(permitted, ambient, new))
                        bprm->cap_elevated = 1;
        }

--

1.7.1