CRED: Fix commit_creds() on a process that has no mm

Fix commit_creds()'s handling of a process that has no mm (such as one that is
calling or has called daemonize()).  commit_creds() should check to see if
task->mm is not NULL before calling set_dumpable() on it.

Reported-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>

diff --git a/kernel/cred.c b/kernel/cred.c
index ff7bc071991c3dd008f5d67078bfde1cefb46bf4..480a61aec805a5430ab4ec8359c78032177572a6 100644 (file)
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -372,7 +372,8 @@ int commit_creds(struct cred *new)
            old->fsuid != new->fsuid ||
            old->fsgid != new->fsgid ||
            !cap_issubset(new->cap_permitted, old->cap_permitted)) {
-               set_dumpable(task->mm, suid_dumpable);
+               if (task->mm)
+                       set_dumpable(task->mm, suid_dumpable);
                task->pdeath_signal = 0;
                smp_wmb();
        }