sched: Fix fork() error path to not crash
In dup_task_struct(), if arch_dup_task_struct() fails, the clean up
code fails to clean up correctly. That's because the clean up
code depends on unininitalized ti->task pointer. We fix this
by making sure that the task and thread_info know about each other
before we attempt to take the error path.
Signed-off-by: Salman Qazi <sqazi@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20120626011815.11323.5533.stgit@dungbeetle.mtv.corp.google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/kernel/fork.c b/kernel/fork.c
index ab5211b..f00e319 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -304,12 +304,17 @@
}
err = arch_dup_task_struct(tsk, orig);
+
+ /*
+ * We defer looking at err, because we will need this setup
+ * for the clean up path to work correctly.
+ */
+ tsk->stack = ti;
+ setup_thread_stack(tsk, orig);
+
if (err)
goto out;
- tsk->stack = ti;
-
- setup_thread_stack(tsk, orig);
clear_user_return_notifier(tsk);
clear_tsk_need_resched(tsk);
stackend = end_of_stack(tsk);