From 164c33c6adee609b8b9062cce4c10f764d0dce13 Mon Sep 17 00:00:00 2001 From: Salman Qazi Date: Mon, 25 Jun 2012 18:18:15 -0700 Subject: [PATCH] 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 Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/20120626011815.11323.5533.stgit@dungbeetle.mtv.corp.google.com Signed-off-by: Ingo Molnar --- kernel/fork.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/kernel/fork.c b/kernel/fork.c index ab5211b9e622..f00e319d8376 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -304,12 +304,17 @@ static struct task_struct *dup_task_struct(struct task_struct *orig) } err = arch_dup_task_struct(tsk, orig); - if (err) - goto out; + /* + * 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; + clear_user_return_notifier(tsk); clear_tsk_need_resched(tsk); stackend = end_of_stack(tsk); -- GitLab