livepatch: RCU protect struct klp_func all the time when used in klp_ftrace_handler()

func->new_func has been accessed after rcu_read_unlock() in klp_ftrace_handler()
and therefore the access was not protected.

Signed-off-by: Petr Mladek <pmladek@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This commit is contained in:
Petr Mladek 2015-02-18 18:02:13 +01:00 committed by Jiri Kosina
parent e0b561ee78
commit c4ce0da8ec

View File

@ -314,12 +314,12 @@ static void notrace klp_ftrace_handler(unsigned long ip,
rcu_read_lock();
func = list_first_or_null_rcu(&ops->func_stack, struct klp_func,
stack_node);
rcu_read_unlock();
if (WARN_ON_ONCE(!func))
return;
goto unlock;
klp_arch_set_pc(regs, (unsigned long)func->new_func);
unlock:
rcu_read_unlock();
}
static int klp_disable_func(struct klp_func *func)