Merge tag 'secureexec-v4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull secureexec update from Kees Cook:
 "This series has the ultimate goal of providing a sane stack rlimit
  when running set*id processes.

  To do this, the bprm_secureexec LSM hook is collapsed into the
  bprm_set_creds hook so the secureexec-ness of an exec can be
  determined early enough to make decisions about rlimits and the
  resulting memory layouts. Other logic acting on the secureexec-ness of
  an exec is similarly consolidated. Capabilities needed some special
  handling, but the refactoring removed other special handling, so that
  was a wash"

* tag 'secureexec-v4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  exec: Consolidate pdeath_signal clearing
  exec: Use sane stack rlimit under secureexec
  exec: Consolidate dumpability logic
  smack: Remove redundant pdeath_signal clearing
  exec: Use secureexec for clearing pdeath_signal
  exec: Use secureexec for setting dumpability
  LSM: drop bprm_secureexec hook
  commoncap: Move cap_elevated calculation into bprm_set_creds
  commoncap: Refactor to remove bprm_secureexec hook
  smack: Refactor to remove bprm_secureexec hook
  selinux: Refactor to remove bprm_secureexec hook
  apparmor: Refactor to remove bprm_secureexec hook
  binfmt: Introduce secureexec flag
  exec: Correct comments about "point of no return"
  exec: Rename bprm->cred_prepared to called_set_creds

1 files changed, 6 insertions, 20 deletions

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 2f2e1338cd3d..ad3b0f53ede0 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -2356,7 +2356,7 @@ static int selinux_bprm_set_creds(struct linux_binprm *bprm)
 
         /* SELinux context only depends on initial program or script and not
          * the script interpreter */
-        if (bprm->cred_prepared)
+        if (bprm->called_set_creds)
                 return 0;
 
         old_tsec = current_security();
@@ -2442,30 +2442,17 @@ static int selinux_bprm_set_creds(struct linux_binprm *bprm)
 
                 /* Clear any possibly unsafe personality bits on exec: */
                 bprm->per_clear |= PER_CLEAR_ON_SETID;
-        }
-
-        return 0;
-}
-
-static int selinux_bprm_secureexec(struct linux_binprm *bprm)
-{
-        const struct task_security_struct *tsec = current_security();
-        u32 sid, osid;
-        int atsecure = 0;
-
-        sid = tsec->sid;
-        osid = tsec->osid;
 
-        if (osid != sid) {
                 /* Enable secure mode for SIDs transitions unless
                    the noatsecure permission is granted between
                    the two SIDs, i.e. ahp returns 0. */
-                atsecure = avc_has_perm(osid, sid,
-                                        SECCLASS_PROCESS,
-                                        PROCESS__NOATSECURE, NULL);
+                rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
+                                  SECCLASS_PROCESS, PROCESS__NOATSECURE,
+                                  NULL);
+                bprm->secureexec |= !!rc;
         }
 
-        return !!atsecure;
+        return 0;
 }
 
 static int match_file(const void *p, struct file *file, unsigned fd)
@@ -6266,7 +6253,6 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
         LSM_HOOK_INIT(bprm_set_creds, selinux_bprm_set_creds),
         LSM_HOOK_INIT(bprm_committing_creds, selinux_bprm_committing_creds),
         LSM_HOOK_INIT(bprm_committed_creds, selinux_bprm_committed_creds),
-        LSM_HOOK_INIT(bprm_secureexec, selinux_bprm_secureexec),
 
         LSM_HOOK_INIT(sb_alloc_security, selinux_sb_alloc_security),
         LSM_HOOK_INIT(sb_free_security, selinux_sb_free_security),