exec: Consolidate dumpability logic

Since it's already valid to set dumpability in the early part of
setup_new_exec(), we can consolidate the logic into a single place.
The BINPRM_FLAGS_ENFORCE_NONDUMP is set during would_dump() calls
before setup_new_exec(), so its test is safe to move as well.

Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>

diff --git a/fs/exec.c b/fs/exec.c
index 7a92885..3006c1c 100644 (file)
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1354,10 +1354,12 @@ void setup_new_exec(struct linux_binprm * bprm)
 
        current->sas_ss_sp = current->sas_ss_size = 0;
 
-       if (!bprm->secureexec)
-               set_dumpable(current->mm, SUID_DUMP_USER);
-       else
+       /* Figure out dumpability. */
+       if (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP ||
+           bprm->secureexec)
                set_dumpable(current->mm, suid_dumpable);
+       else
+               set_dumpable(current->mm, SUID_DUMP_USER);
 
        arch_setup_new_exec();
        perf_event_exec();
@@ -1371,9 +1373,6 @@ void setup_new_exec(struct linux_binprm * bprm)
 
        if (bprm->secureexec) {
                current->pdeath_signal = 0;
-       } else {
-               if (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP)
-                       set_dumpable(current->mm, suid_dumpable);
        }
 
        /* An exec changes our domain. We are no longer part of the thread