From: Breno Leitao <leitao@debian.org>
To: Gustavo Luiz Duarte <gustavold@gmail.com>
Cc: Andrew Lunn <andrew+netdev@lunn.ch>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@kernel.org>,
Jakub Kicinski <kuba@kernel.org>,
Paolo Abeni <pabeni@redhat.com>,
Stephen Hemminger <stephen@networkplumber.org>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH net v5 3/4] netconsole: recheck device registration after waiting for carrier
Date: Tue, 3 Nov 2026 04:09:21 -0800 [thread overview]
Message-ID: <aunO6ayPWIou9euS@gmail.com> (raw)
In-Reply-To: <20261102-netcons-fixes-v5-3-bdada2f03563@gmail.com>
On Mon, Nov 02, 2026 at 07:54:51PM +0000, Gustavo Luiz Duarte wrote:
> netcons_netpoll_setup() drops RTNL while it waits for carrier when the
> device is not yet up. If the device is unregistered in that window, the
> NETDEV_UNREGISTER notifier runs before np->dev is set and has nothing
> to match.
>
> We might then end up setting up netpoll on a device that is being
> unregistered while holding a reference to it, stalling
> unregister_netdevice() in netdev_wait_allrefs_any().
>
> Add a check to confirm the device is still registered once we retake
> RTNL. Release the device reference and return -ENODEV otherwise.
>
> Closes: https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20261012-netcons-fixes-v3-1-1aac85ed7665@gmail.com
> Signed-off-by: Gustavo Luiz Duarte <gustavold@gmail.com>
Reviewed-by: Breno Leitao <leitao@debian.org>
next prev parent reply other threads:[~2026-11-03 12:09 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-02 19:54 [PATCH net v5 0/4] netconsole: fix target enable race and configfs read locking Gustavo Luiz Duarte
2026-11-02 19:54 ` [PATCH net v5 1/4] netconsole: finish enabling the target before releasing RTNL Gustavo Luiz Duarte
2026-11-03 12:08 ` Breno Leitao
2026-11-02 19:54 ` [PATCH net v5 2/4] netconsole: read np.dev under target_list_lock in local_mac_show() Gustavo Luiz Duarte
2026-11-03 12:08 ` Breno Leitao
2026-11-02 19:54 ` [PATCH net v5 3/4] netconsole: recheck device registration after waiting for carrier Gustavo Luiz Duarte
2026-11-03 12:09 ` Breno Leitao [this message]
2026-11-02 19:54 ` [PATCH net v5 4/4] netconsole: stop waiting for carrier once the device is unregistered Gustavo Luiz Duarte
2026-11-03 12:28 ` Breno Leitao
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