From: Paolo Abeni <pabeni@redhat.com>
To: Jakub Kicinski <kuba@kernel.org>,
Simon Wunderlich <sw@simonwunderlich.de>
Cc: davem@davemloft.net, netdev@vger.kernel.org,
b.a.t.m.a.n@lists.open-mesh.org,
Vladislav Efanov <VEfanov@ispras.ru>,
stable@kernel.org
Subject: Re: [PATCH 1/1] batman-adv: Broken sync while rescheduling delayed work
Date: Thu, 08 Jun 2023 11:27:31 +0200 [thread overview]
Message-ID: <6a36f208b961181df9a0c611a6f5ffc4c76911f6.camel@redhat.com> (raw)
In-Reply-To: <20230607220126.26c6ee40@kernel.org>
On Wed, 2023-06-07 at 22:01 -0700, Jakub Kicinski wrote:
> On Wed, 7 Jun 2023 17:55:15 +0200 Simon Wunderlich wrote:
> > The reason for these issues is the lack of synchronization. Delayed
> > work (batadv_dat_purge) schedules new timer/work while the device
> > is being deleted. As the result new timer/delayed work is set after
> > cancel_delayed_work_sync() was called. So after the device is freed
> > the timer list contains pointer to already freed memory.
>
> I guess this is better than status quo but is the fix really complete?
> We're still not preventing the timer / work from getting scheduled
> and staying alive after the netdev has been freed, right?
I *think* this specific use case does not expose such problem, as the
delayed work is (AFAICS) scheduled only at device creation time and by
the work itself, it should never be re-scheduled after
cancel_delayed_work_sync()
Cheers,
Paolo
next prev parent reply other threads:[~2023-06-08 9:35 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-07 15:55 [PATCH 0/1] pull request for net: batman-adv 2023-06-07 Simon Wunderlich
[not found] ` <20230607155515.548120-2-sw@simonwunderlich.de>
2023-06-08 5:00 ` [PATCH 1/1] batman-adv: Broken sync while rescheduling delayed work patchwork-bot+netdevbpf
2023-06-08 5:01 ` Jakub Kicinski
2023-06-08 5:24 ` Keller, Jacob E
2023-06-08 9:01 ` Vlad Efanov
2023-06-08 9:27 ` Paolo Abeni [this message]
2023-06-08 16:57 ` Sven Eckelmann
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