From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj2-f9.google.com (mail-pj2-f9.google.com [74.125.227.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0ADE1368D76 for ; Wed, 22 Jul 2026 22:07:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.227.137 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784758081; cv=none; b=OlWklEj2+vbdrZAM+VP2pAjNtFGPVmDZc4rQnBJ1RsD+6w8C8bUWwV1V746jr97vhyxDdGgMcZ4Wq6WywxHTbmtXp/EYN7tqHKQF27uX7lE8tauf8gbJOjckOyi5rFge28pEEDn6e5A8t9naRLB0iWwLdjqULoHItPsPuNcdP1U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784758081; c=relaxed/simple; bh=c4Obeuqqrr4bY3iX1bjSDpquaWYjAyztcT+fEJSg1K8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=HVeDuWyjg/BOeaxDsTExpQoZlndG2HAw5OSzA57QP8SdKCbwNOFfwKR2NTM/iAqdHKoXNg4o/yZrAkYyAauwCc0XW1L0slqOp1h7EW/MxhmqMTjBSu0AxntojhXMOb7Fk1BPCB2m1MJvqs5StvfPtVC3QuvUYbFnJoDjHB3kUJE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=IXeG7YuX; arc=none smtp.client-ip=74.125.227.137 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="IXeG7YuX" Received: by mail-pj2-f9.google.com with SMTP id 98e67ed59e1d1-38eaa0c5df6so104338a91.0 for ; Wed, 22 Jul 2026 15:07:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1784758079; x=1785362879; darn=vger.kernel.org; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:from:to:cc:subject :date:message-id:reply-to:content-type; bh=8B2XeyxAvEwsooW1amp2RehjuZYYpC3Hm5dyn1YxDOg=; b=IXeG7YuXsXONjpKzIDygNtAZKQQVnwSOoAIlzlTwO7CoAZWULWRLzLIlsplzP4lLlt 8JVOuQEIpCsFUvi06p3lpStJ5TI/tamhPRhownSsOChMYJkOqBCJ7SUXyIqhAqpXNvnL 0p7/cXoxsIDcQm3UDlJhjK7cfFrSejKWfnap5Savcpu3UlM5ydTgUUk4crAyeoPHV6Pj HWnqaE6+e1ncoZMw59qX0RcDMqs796niYx9NXPACNVXRBov5+0jFasaBozKFO/Kd6W3U +nZtbp/xHTubDEACyOs3DRUHJkP0GzNH2jw86IOguWbnmz0L+AVNi+A92/nsdgcZz+Fe FIMg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1784758079; x=1785362879; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=8B2XeyxAvEwsooW1amp2RehjuZYYpC3Hm5dyn1YxDOg=; b=jbNn4yjoxsFRI/pqppMJUyHBTScQuv66b4ywSTOb2XvV29TTDhrcotZBRMLbRqHWVu VuIotV5WtkAdzxx9VwvnYJAXmBoPBwFeLIIRJLwN29PHzXmam7yMG0a/LAUNRrk8vflb E20xH1u6Ac98kf4OUaJ7mhEuzkWZIJr8loBuhzovqShcl0kG7+vSM8L8ggeX/znHe8G+ CVoCcG7lDwrb56PPkdrgT2PxoHTDPnbi2quRZUXlq05ji/Ju/EX7PJgVNv1VYDrLQ1Ah F4dH0C4nvAFtgmwnO4hSyPBMVX1tygD/rgH7cTjDidwboVvLyOOE4BAyBcdrOoT1vo84 15uA== X-Forwarded-Encrypted: i=1; AHgh+RrHkm9QhAcCBl6l94vozdfnWU27BOhawV+0Rvb9RrMwF0x7IVpWpjUveutwsXInvZYvceXG+jY=@vger.kernel.org X-Gm-Message-State: AOJu0YzonLhB1sOfBuxljO4UhQ2TdhfFFprqF7FY/WK4SW7Wgl+BJRqk rcpmQGMvuIFrFZW+b3VDKZNXarDzGXJBtpxQq4wqqoSjGsxheOCjxcNp X-Gm-Gg: AR+sD12awrA1y+SBzn7bugMpsBMFlxhYUmX+vnAorO7X6MvYz4bvmEXJ/j+7Jk2CiwP iWieUtZB4mfl/D9rAjblEXK5Q3mHZKRFFzsyXmE7h0HaJINd2BRNMB9pHVQ5vrIsfN19ZEIlAW5 1hI5RKjGT5JLUWhV7UCfM6M5f9/J96b44/BDEIyD2RgPlOmp8UeTNBfMt/cePGAPBqNkDtzeiDh yQJF4AJNJxpQ1CMZ3rrkLy1rh5OCG8qaq/oJnvIHF/EhJnGJVIDjaRY3JCDyCcsgTIlDfOOATza 7BBxeMHmWX94HqpM95qJqzc6Ss7wswEOfC7Pe7If5AszDQRrTiCguyexgTqFhZwdEcQojzuXbio nCEvN5Pb4jqhZ7hNZ2pZRDd9kj2p2KuxkEguCyLSBM4vpskZatyKsKlLsI+8aXpF/bqUO+Ln3m8 juhmrdFA== X-Received: by 2002:a17:90b:3f4e:b0:384:927f:3db9 with SMTP id 98e67ed59e1d1-38ec8389dc3mr103539a91.1.1784758079276; Wed, 22 Jul 2026 15:07:59 -0700 (PDT) Received: from localhost ([2a03:2880:2ff:72::]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-38e92169cebsm4014911a91.11.2026.07.22.15.07.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 22 Jul 2026 15:07:58 -0700 (PDT) Date: Wed, 22 Jul 2026 15:07:41 -0700 From: Stanislav Fomichev To: Kuniyuki Iwashima Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, netdev@vger.kernel.org, pabeni@redhat.com Subject: Re: [PATCH net-next v2 1/6] net: hold instance lock around NETDEV_DOWN/GOING_DOWN Message-ID: References: <20260702224150.3730033-2-sdf@fomichev.me> <20260714113658.2023117-1-kuniyu@google.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20260714113658.2023117-1-kuniyu@google.com> On 07/14, Kuniyuki Iwashima wrote: > From: Stanislav Fomichev > Date: Thu, 2 Jul 2026 15:41:45 -0700 > > Mirror what call_netdevice_register_net_notifiers does but for the > > teardown. Cover only DOWN and GOING_DOWN. UNREGISTER is still unlocked > > because of the SW devices using dev_xxx methods. > > > > Signed-off-by: Stanislav Fomichev > > --- > > net/core/dev.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/net/core/dev.c b/net/core/dev.c > > index 4b3d5cfdf6e0..9d49493f4fb5 100644 > > --- a/net/core/dev.c > > +++ b/net/core/dev.c > > @@ -1912,9 +1912,11 @@ static void call_netdevice_unregister_notifiers(struct notifier_block *nb, > > struct net_device *dev) > > { > > if (dev->flags & IFF_UP) { > > + netdev_lock_ops(dev); > > call_netdevice_notifier(nb, NETDEV_GOING_DOWN, > > dev); > > call_netdevice_notifier(nb, NETDEV_DOWN, dev); > > FYI, this is the report I mentioned yesterday. > > Most likely false-positive because open/close, which takes RTNL, > are never called under epoll lock. > > https://lore.kernel.org/netdev/6a55fc56.c90005c7.37d349.001c.GAE@google.com/ Sorry, just spotted this. I do agree that it looks like a false positive, so not gonna invest my time unless syzbot finds a repro :-)