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Date: Fri, 10 Nov 2023 11:52:24 -0800
From: Jakub Kicinski <kuba@kernel.org>
To: Richard Cochran <richardcochran@gmail.com>
Cc: Eric Dumazet <edumazet@google.com>, "David S . Miller"
 <davem@davemloft.net>, Paolo Abeni <pabeni@redhat.com>,
 netdev@vger.kernel.org, eric.dumazet@gmail.com
Subject: Re: [PATCH net] ptp: annotate data-race around q->head and q->tail
Message-ID: <20231110115224.3d2f180c@kernel.org>
In-Reply-To: <ZU5j2V9aUae0FE1o@hoboy.vegasvil.org>
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On Fri, 10 Nov 2023 09:09:45 -0800 Richard Cochran wrote:
> > I do not see how races are solved... Shouldn't
> > pccontext->private_clkdata be protected by RCU ?  
> 
> Yeah, the test is useless, because the memory is allocated in open()
> and later freed in release().  During ioctl() the pointer must be
> valid.
> 
> However, there was a bogus call to ptp_release() in the read() method,
> but that has now been removed, and so the test is now bogus.

Meaning we should revert 8a4f030dbced ("ptp: Fixes a null pointer
dereference in ptp_ioctl") ?