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>
This commit is contained in:
Jiri Kosina 2009-10-12 11:25:56 +02:00
parent ff9b00a226
commit b0e14951ee

View File

@ -47,10 +47,9 @@ static ssize_t hidraw_read(struct file *file, char __user *buffer, size_t count,
char *report;
DECLARE_WAITQUEUE(wait, current);
mutex_lock(&list->read_mutex);
while (ret == 0) {
mutex_lock(&list->read_mutex);
if (list->head == list->tail) {
add_wait_queue(&list->hidraw->wait, &wait);
set_current_state(TASK_INTERRUPTIBLE);