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Date: Thu, 28 Aug 2025 08:28:52 +0200
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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Eric Dumazet <edumazet@google.com>
Cc: "David S . Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Simon Horman <horms@kernel.org>,
	Jamal Hadi Salim <jhs@mojatatu.com>,
	Cong Wang <xiyou.wangcong@gmail.com>, Jiri Pirko <jiri@resnulli.us>,
	netdev@vger.kernel.org, eric.dumazet@gmail.com,
	syzbot+72db9ee39db57c3fecc5@syzkaller.appspotmail.com
Subject: Re: [PATCH v2 net] net_sched: gen_estimator: fix est_timer() vs
 CONFIG_PREEMPT_RT=y
Message-ID: <20250828062852.7LnXu1qK@linutronix.de>
References: <20250827162352.3960779-1-edumazet@google.com>
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In-Reply-To: <20250827162352.3960779-1-edumazet@google.com>

On 2025-08-27 16:23:52 [+0000], Eric Dumazet wrote:
> syzbot reported a WARNING in est_timer() [1]
>=20
> Problem here is that with CONFIG_PREEMPT_RT=3Dy, timer callbacks
> can be preempted.
>=20
> Adopt preempt_disable_nested()/preempt_enable_nested() to fix this.
=E2=80=A6
> Fixes: d2d6422f8bd1 ("x86: Allow to enable PREEMPT_RT.")
> Reported-by: syzbot+72db9ee39db57c3fecc5@syzkaller.appspotmail.com
> Closes: https://lore.kernel.org/netdev/68adf6fa.a70a0220.3cafd4.0000.GAE@=
google.com/T/#u
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

Sebastian