From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jakub Kicinski <kuba@kernel.org>
Subject: Re: [PATCH net v2] net: rose: fix UAF bug caused by
 rose_t0timer_expiry
Date: Wed, 6 Jul 2022 19:02:37 -0700
Message-ID: <20220706190237.477f24ee@kernel.org>
References: <20220705125610.77971-1-duoming@zju.edu.cn>
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To: Duoming Zhou <duoming@zju.edu.cn>
Cc: linux-hams@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, ralf@linux-mips.org, davem@davemloft.net, edumazet@google.com, pabeni@redhat.com

On Tue,  5 Jul 2022 20:56:10 +0800 Duoming Zhou wrote:
> +	del_timer_sync(&rose_neigh->t0timer);

/**
 * del_timer_sync - deactivate a timer and wait for the handler to finish.
[...]
 * Synchronization rules: Callers must prevent restarting of the timer,
 * otherwise this function is meaningless.

how is the restarting prevented? If I'm looking right 
rose_t0timer_expiry() rearms the timer.