Re: [PATCH] nbd: Fix NULL pointer in flush_workqueue

hi，Markus 在 2021/1/29 3:42, Markus Elfring 写道: … +++ b/drivers/block/nbd.c @@ -2011,12 +2011,20 @@ static int nbd_genl_disconnect(struct sk_buff *skb, struct genl_info *info) index); return -EINVAL; } + mutex_lock(>config_lock); if

[PATCH] nbd: Fix NULL pointer in flush_workqueue

Open /dev/nbdX first, the config_refs will be 1 and the pointers in nbd_device are still null. Disconnect /dev/nbdX, then reference a null recv_workq. The protection by config_refs in nbd_genl_disconnect is useless. [ 656.366194] BUG: kernel NULL pointer dereference, address: 0020 [