cpu_stop_park() does cpu_stop_signal_done() but leaves the work on
stopper->works. The owner of this work can free/reuse this memory
right after that and corrupt the list, so if this CPU becomes online
again cpu_stopper_thread() will crash.
Signed-off-by: Oleg Nesterov <o...@redhat.com>
---
kernel/stop_machine.c | 6 ++++--
1 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 9a70def..12484e5 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -462,13 +462,15 @@ static void cpu_stop_create(unsigned int cpu)
static void cpu_stop_park(unsigned int cpu)
{
struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu);
- struct cpu_stop_work *work;
+ struct cpu_stop_work *work, *tmp;
unsigned long flags;
/* drain remaining works */
spin_lock_irqsave(&stopper->lock, flags);
- list_for_each_entry(work, &stopper->works, list)
+ list_for_each_entry_safe(work, tmp, &stopper->works, list) {
+ list_del_init(&work->list);
cpu_stop_signal_done(work->done, false);
+ }
stopper->enabled = false;
spin_unlock_irqrestore(&stopper->lock, flags);
}
--
1.7.1
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