From: Josef Bacik <josef@toxicpanda.com>
To: Yu Kuai <yukuai3@huawei.com>
Cc: axboe@kernel.dk, ming.lei@redhat.com,
linux-block@vger.kernel.org, nbd@other.debian.org,
linux-kernel@vger.kernel.org, yi.zhang@huawei.com
Subject: Re: [PATCH -next v3 1/6] nbd: call genl_unregister_family() first in nbd_cleanup()
Date: Mon, 23 May 2022 10:13:50 -0400 [thread overview]
Message-ID: <YouWnpZxnGBiXq6X@localhost.localdomain> (raw)
In-Reply-To: <20220521073749.3146892-2-yukuai3@huawei.com>
On Sat, May 21, 2022 at 03:37:44PM +0800, Yu Kuai wrote:
> Otherwise there may be race between module removal and the handling of
> netlink command, which can lead to the oops as shown below:
>
> BUG: kernel NULL pointer dereference, address: 0000000000000098
> Oops: 0002 [#1] SMP PTI
> CPU: 1 PID: 31299 Comm: nbd-client Tainted: G E 5.14.0-rc4
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
> RIP: 0010:down_write+0x1a/0x50
> Call Trace:
> start_creating+0x89/0x130
> debugfs_create_dir+0x1b/0x130
> nbd_start_device+0x13d/0x390 [nbd]
> nbd_genl_connect+0x42f/0x748 [nbd]
> genl_family_rcv_msg_doit.isra.0+0xec/0x150
> genl_rcv_msg+0xe5/0x1e0
> netlink_rcv_skb+0x55/0x100
> genl_rcv+0x29/0x40
> netlink_unicast+0x1a8/0x250
> netlink_sendmsg+0x21b/0x430
> ____sys_sendmsg+0x2a4/0x2d0
> ___sys_sendmsg+0x81/0xc0
> __sys_sendmsg+0x62/0xb0
> __x64_sys_sendmsg+0x1f/0x30
> do_syscall_64+0x3b/0xc0
> entry_SYSCALL_64_after_hwframe+0x44/0xae
> Modules linked in: nbd(E-)
>
> Signed-off-by: Hou Tao <houtao1@huawei.com>
> Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Thanks,
Josef
next prev parent reply other threads:[~2022-05-23 14:14 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-21 7:37 [PATCH -next v3 0/6] nbd: bugfix and cleanup patches Yu Kuai
2022-05-21 7:37 ` [PATCH -next v3 1/6] nbd: call genl_unregister_family() first in nbd_cleanup() Yu Kuai
2022-05-23 14:13 ` Josef Bacik [this message]
2022-05-21 7:37 ` [PATCH -next v3 2/6] nbd: fix race between nbd_alloc_config() and module removal Yu Kuai
2022-05-23 14:14 ` Josef Bacik
2022-05-21 7:37 ` [PATCH -next v3 3/6] nbd: don't clear 'NBD_CMD_INFLIGHT' flag if request is not completed Yu Kuai
2022-05-23 14:12 ` Josef Bacik
2022-05-24 1:07 ` Yu Kuai
2022-05-24 1:51 ` Yu Kuai
2022-05-21 7:37 ` [PATCH -next v3 4/6] nbd: fix io hung while disconnecting device Yu Kuai
2022-05-23 14:15 ` Josef Bacik
2022-05-21 7:37 ` [PATCH -next v3 5/6] nbd: fix possible overflow on 'first_minor' in nbd_dev_add() Yu Kuai
2022-05-23 14:15 ` Josef Bacik
2022-05-21 7:37 ` [PATCH -next v3 6/6] nbd: use pr_err to output error message Yu Kuai
2022-05-23 14:16 ` Josef Bacik
2022-05-28 12:20 ` [PATCH -next v3 0/6] nbd: bugfix and cleanup patches Jens Axboe
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