From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
To: "Jouni Högander" <jouni.hogander@unikie.com>
Cc: syzbot <syzbot+30209ea299c09d8785c9@syzkaller.appspotmail.com>,
YueHaibing <yuehaibing@huawei.com>, Julian Anastasov <ja@ssi.bg>,
ddstreet@ieee.org, dvyukov@google.com,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
syzkaller-bugs@googlegroups.com, Hulk Robot <hulkci@huawei.com>,
"David S. Miller" <davem@davemloft.net>,
Lukas Bulwahn <lukas.bulwahn@gmail.com>
Subject: Re: unregister_netdevice: waiting for DEV to become free (2)
Date: Thu, 5 Dec 2019 20:00:35 +0900 [thread overview]
Message-ID: <c03d8353-ae34-2f84-68d3-0153873ffc3e@i-love.sakura.ne.jp> (raw)
In-Reply-To: <87y2vrgkij.fsf@unikie.com>
On 2019/12/05 19:00, Jouni Högander wrote:
>> diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
>> index ae3bcb1540ec..562d06c274aa 100644
>> --- a/net/core/net-sysfs.c
>> +++ b/net/core/net-sysfs.c
>> @@ -1459,14 +1459,14 @@ static int netdev_queue_add_kobject(struct net_device *dev, int index)
>> struct kobject *kobj = &queue->kobj;
>> int error = 0;
>>
>> + dev_hold(queue->dev);
>> +
>> kobj->kset = dev->queues_kset;
>> error = kobject_init_and_add(kobj, &netdev_queue_ktype, NULL,
>> "tx-%u", index);
>> if (error)
>> goto err;
>>
>> - dev_hold(queue->dev);
>> -
>> #ifdef CONFIG_BQL
>> error = sysfs_create_group(kobj, &dql_group);
>> if (error)
>
> Now after reproducing the issue I think this is actually proper fix for
> the issue. It's not related to missing error handling in in
> tun_set_real_num_queues as I commented earlier. Can you prepare patch
> for this?
You can write the patch; I don't know about commit a3e23f719f5c4a38
("net-sysfs: call dev_hold if kobject_init_and_add success").
I was wondering how can the caller tell whether to drop the refcount, for
the caller won't be able to know which one (kobject_init_and_add() or
sysfs_create_group()) returned an error. Therefore, always taking the
refcount seems to be a proper fix...
next prev parent reply other threads:[~2019-12-05 11:00 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <00000000000056268e05737dcb95@google.com>
[not found] ` <000000000000c5b63005737f290d@google.com>
2018-08-15 20:41 ` unregister_netdevice: waiting for DEV to become free (2) Dmitry Vyukov
2018-08-20 4:31 ` syzbot
2018-08-20 12:55 ` Julian Anastasov
2018-08-21 5:40 ` Cong Wang
2018-08-22 4:11 ` Julian Anastasov
2019-04-15 13:36 ` Tetsuo Handa
2019-04-15 15:35 ` David Ahern
2019-04-21 20:41 ` Stephen Suryaputra
2019-04-22 14:58 ` David Ahern
2019-04-22 16:04 ` Eric Dumazet
2019-04-22 16:09 ` Eric Dumazet
2019-04-16 14:00 ` Tetsuo Handa
2019-04-26 13:43 ` Tetsuo Handa
2019-04-27 17:16 ` David Ahern
2019-04-27 22:33 ` Tetsuo Handa
2019-04-27 23:52 ` Eric Dumazet
2019-04-28 4:22 ` Tetsuo Handa
2019-04-28 15:04 ` Eric Dumazet
2019-04-29 18:34 ` David Ahern
2019-04-29 18:43 ` David Ahern
2019-05-01 13:38 ` Tetsuo Handa
2019-05-01 14:52 ` David Ahern
2019-05-01 16:16 ` Tetsuo Handa
2019-05-04 14:52 ` [PATCH] ipv4: Delete uncached routes upon unregistration of loopback device Tetsuo Handa
2019-05-04 15:56 ` Eric Dumazet
2019-05-04 17:09 ` Tetsuo Handa
2019-05-04 17:24 ` Eric Dumazet
2019-05-04 20:13 ` Julian Anastasov
2019-11-28 9:56 ` unregister_netdevice: waiting for DEV to become free (2) Tetsuo Handa
2019-11-29 5:54 ` Lukas Bulwahn
2019-11-29 6:51 ` Jouni Högander
2019-12-05 10:00 ` Jouni Högander
2019-12-05 11:00 ` Tetsuo Handa [this message]
2019-12-16 11:12 ` Tetsuo Handa
2019-12-17 7:08 ` Jouni Högander
2019-10-11 10:14 ` Tetsuo Handa
2019-10-11 15:12 ` Alexei Starovoitov
2019-10-16 10:34 ` Toke Høiland-Jørgensen
2019-11-15 9:43 ` Tetsuo Handa
2019-11-21 11:36 ` Toke Høiland-Jørgensen
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