From: Jakub Kicinski <kuba@kernel.org>
To: "Nikola Z. Ivanov" <zlatistiv@gmail.com>
Cc: jiri@resnulli.us, andrew+netdev@lunn.ch, davem@davemloft.net,
edumazet@google.com, pabeni@redhat.com, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, skhan@linuxfoundation.org,
david.hunter.linux@gmail.com, khalid@kernel.org,
linux-kernel-mentees@lists.linuxfoundation.org,
syzbot+a2a3b519de727b0f7903@syzkaller.appspotmail.com
Subject: Re: [PATCH net] team: Move team device type change at the end of team_port_add
Date: Tue, 11 Nov 2025 17:13:41 -0800 [thread overview]
Message-ID: <20251111171341.4c6d69be@kernel.org> (raw)
In-Reply-To: <20251112003444.2465-1-zlatistiv@gmail.com>
On Wed, 12 Nov 2025 02:34:44 +0200 Nikola Z. Ivanov wrote:
> Attempting to add a port device that is already up will expectedly fail,
> but not before modifying the team device header_ops.
>
> In the case of the syzbot reproducer the gre0 device is
> already in state UP when it attempts to add it as a
> port device of team0, this fails but before that
> header_ops->create of team0 is changed from eth_header to ipgre_header
> in the call to team_dev_type_check_change.
>
> Later when we end up in ipgre_header() struct *ip_tunnel points to nonsense
> as the private data of the device still holds a struct team.
>
> Move team_dev_type_check_change down where all other checks have passed
> as it changes the dev type with no way to restore it in case
> one of the checks that follow it fail.
Since this is a bug fix it must have a Fixes tag pointing to first
commit where the issue could be reproduced.
Please make sure to have a quick read of (at least the tl;dr of)
https://www.kernel.org/doc/html/next/process/maintainer-netdev.html
before reposting.
--
pw-bot: cr
next prev parent reply other threads:[~2025-11-12 1:13 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-12 0:34 [PATCH net] team: Move team device type change at the end of team_port_add Nikola Z. Ivanov
2025-11-12 1:13 ` Jakub Kicinski [this message]
2025-11-18 11:46 ` Paolo Abeni
2025-11-19 16:10 ` Jiri Pirko
2025-11-19 16:24 ` Nikola Z. Ivanov
2025-11-19 17:03 ` Jiri Pirko
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