From: Jakub Kicinski <kuba@kernel.org>
To: Gong Ruiqi <gongruiqi1@huawei.com>
Cc: <davem@davemloft.net>, <netdev@vger.kernel.org>,
<edumazet@google.com>, <pabeni@redhat.com>,
lianhui tang <bluetlh@gmail.com>, <kuniyu@amazon.co.jp>,
<rshearma@brocade.com>
Subject: Re: [PATCH net] net: mpls: fix stale pointer if allocation fails during device rename
Date: Tue, 14 Feb 2023 13:23:31 -0800 [thread overview]
Message-ID: <20230214132331.526f4fb7@kernel.org> (raw)
In-Reply-To: <d85f25cf-3c37-dff2-85fd-f8f3a5a57645@huawei.com>
On Tue, 14 Feb 2023 17:33:36 +0800 Gong Ruiqi wrote:
> Just be curious: would this be a simpler solution?
>
> @@ -1439,6 +1439,7 @@ static void mpls_dev_sysctl_unregister(struct
> net_device *dev,
>
> table = mdev->sysctl->ctl_table_arg;
> unregister_net_sysctl_table(mdev->sysctl);
> + mdev->sysctl = NULL;
> kfree(table);
>
> mpls_netconf_notify_devconf(net, RTM_DELNETCONF, 0, mdev);
>
> However I'm not sure if we need to preserve the old value of
> mdev->sysctl after we unregister it.
It'd work too, I decided to limit the zeroing to the exception case
because of recent discussions on the list. The argument there was that
zeroing in cases were we don't expect it to be necessary may hide bugs.
We generally try to avoid defensive programming in the kernel.
next prev parent reply other threads:[~2023-02-14 21:23 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-14 6:53 [PATCH net] net: mpls: fix stale pointer if allocation fails during device rename Jakub Kicinski
2023-02-14 9:33 ` Gong Ruiqi
2023-02-14 21:23 ` Jakub Kicinski [this message]
2023-02-15 6:29 ` Gong Ruiqi
2023-02-15 10:30 ` patchwork-bot+netdevbpf
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