Oleg Nesterov 704b836cbf mm_for_maps: take ->cred_guard_mutex to fix the race with exec
The problem is minor, but without ->cred_guard_mutex held we can race
with exec() and get the new ->mm but check old creds.

Now we do not need to re-check task->mm after ptrace_may_access(), it
can't be changed to the new mm under us.

Strictly speaking, this also fixes another very minor problem. Unless
security check fails or the task exits mm_for_maps() should never
return NULL, the caller should get either old or new ->mm.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-08-10 20:49:26 +10:00
..
2009-05-15 15:32:45 +02:00
2007-10-17 08:42:48 -07:00
2009-03-30 15:21:57 +02:00
2009-01-05 12:27:44 +03:00