From: Qingfang Deng <dqfext@gmail.com>
To: Eric Dumazet <edumazet@google.com>
Cc: Andrew Lunn <andrew+netdev@lunn.ch>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Paolo Abeni <pabeni@redhat.com>,
Pablo Neira Ayuso <pablo@netfilter.org>,
Felix Fietkau <nbd@nbd.name>,
linux-ppp@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH net] ppp: fix race conditions in ppp_fill_forward_path
Date: Tue, 12 Aug 2025 17:38:02 +0800 [thread overview]
Message-ID: <CALW65jYNMNArwzmpHhYj3fpfL0Oz2fRYsJz0JMDUnyByu-8z3w@mail.gmail.com> (raw)
In-Reply-To: <CALW65jZ-uBWOkxPVMQc3Yg-KEoVRdPQYVC3+q5MiQbvpDZBKTQ@mail.gmail.com>
On Mon, Aug 11, 2025 at 5:35 PM Qingfang Deng <dqfext@gmail.com> wrote:
>
> On Mon, Aug 11, 2025 at 5:19 PM Eric Dumazet <edumazet@google.com> wrote:
> >
> > On Mon, Aug 11, 2025 at 1:44 AM Qingfang Deng <dqfext@gmail.com> wrote:
> > It is unclear if rcu_read_lock() is held at this point.
> >
> > list_first_or_null_rcu() does not have a builtin __list_check_rcu()
>
> ndo_fill_forward_path() is called by nf_tables chains, which is inside
> an RCU critical section.
Update: mtk_flow_get_wdma_info() in mtk_ppe_offload.c calls
dev_fill_forward_path() in process context without RCU, so
ppp_fill_forward_path() can be called from two different contexts.
Should I add rcu_read_lock() to mtk_flow_get_wdma_info() or
ppp_fill_forward_path()?
next prev parent reply other threads:[~2025-08-12 9:38 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-11 8:44 [PATCH net] ppp: fix race conditions in ppp_fill_forward_path Qingfang Deng
2025-08-11 9:19 ` Eric Dumazet
2025-08-11 9:35 ` Qingfang Deng
2025-08-12 9:38 ` Qingfang Deng [this message]
2025-08-12 13:02 ` Pablo Neira Ayuso
2025-08-13 1:46 ` Qingfang Deng
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