HID: fix possible deadlock in hidraw_read



If the loop in hidraw_read() loops more than once, then we might
end up trying to acquire already locked mutex, casuing a deadlock.

Reported-by: iceberg <iceberg@ispras.ru>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

parent ff9b00a2

drivers/hid/hidraw.c

+2 −3

Original line number	Diff line number	Diff line
		@@ -47,10 +47,9 @@ static ssize_t hidraw_read(struct file file, char __user buffer, size_t count,
		char *report;
		DECLARE_WAITQUEUE(wait, current);

		while (ret == 0) {

		mutex_lock(&list->read_mutex);

		while (ret == 0) {
		if (list->head == list->tail) {
		add_wait_queue(&list->hidraw->wait, &wait);
		set_current_state(TASK_INTERRUPTIBLE);