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From: Jakub Kicinski <kuba@kernel.org>
To: Lukasz Majewski <lukma@denx.de>
Cc: Jeongjun Park <aha310510@gmail.com>,
	davem@davemloft.net, edumazet@google.com, pabeni@redhat.com,
	horms@kernel.org, ricardo@marliere.net, m-karicheri2@ti.com,
	n.zhandarovich@fintech.ru, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	syzbot+02a42d9b1bd395cbcab4@syzkaller.appspotmail.com
Subject: Re: [PATCH net] net: hsr: prevent NULL pointer dereference in hsr_proxy_announce()
Date: Wed, 11 Sep 2024 07:43:25 -0700	[thread overview]
Message-ID: <20240911074325.55704611@kernel.org> (raw)
In-Reply-To: <20240911100007.31d600fc@wsk>

On Wed, 11 Sep 2024 10:00:07 +0200 Lukasz Majewski wrote:
> > The structs have no refcounting - should the timers be deleted with
> > _sync() inside hsr_check_announce()?  
> 
> The timers don't need to be conditionally enabled (and removed) as we
> discussed it previously (as they only do useful work when they are
> configured and almost take no resources when declared during the
> driver probe).

My concern is admittedly quite theoretical, and perhaps completely
impossible given current RCU implementation. But what I was saying
is that timer may be running, and interrupted by a very long running
interrupt, say on CPU 0. Then, say, we unregister and free hsr_dev on 
CPU 1. When CPU 0 resumes running the timer code it will UAF on hsr_dev.
Again, probably completely theoretical.

> Anyway:
> 
> Acked-by: Lukasz Majewski <lukma@denx.de>

Thanks!

  parent reply	other threads:[~2024-09-11 14:43 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-09-07 19:03 [PATCH net] net: hsr: prevent NULL pointer dereference in hsr_proxy_announce() Jeongjun Park
2024-09-09  8:40 ` Simon Horman
2024-09-09  8:58 ` Lukasz Majewski
2024-09-11  2:15   ` Jakub Kicinski
2024-09-11  8:00     ` Lukasz Majewski
2024-09-11  8:21       ` Simon Horman
2024-09-11 14:43       ` Jakub Kicinski [this message]
2024-09-11 23:20 ` patchwork-bot+netdevbpf

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