From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f49.google.com (mail-wm1-f49.google.com [209.85.128.49]) (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 6E831405AB0 for ; Wed, 25 Mar 2026 17:24:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.49 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774459496; cv=none; b=acyh7dnlCyWwamHcKrmfXurZFtzx4w1/WvrQfRF65YJ8M7r8PtsqoCQ5Tskae3nYpuQuJ6gaN5xY4CEGTdlqHWdzxI1cmYmm8nTLsGpbOrGRx7JqbkWQXtLlYvTebalVgI6mX8K6LjguLoQEE1VALka+D5UOECzo4GcEalDmV88= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774459496; c=relaxed/simple; bh=WJCHadKIGcaNougMBQMInd24II9CRRJ+fXNCPrZLcj4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=oGh/FobFN2GMDz5Y2LzoxBHVDk7H03sEqrqOsmjztqI2/bmryi3qi05Wwntl6hP2qi+28CRQKUW7PNXFQak7wRAin2x14xvlDsUuzzqBxcSGJkop7WKJUitPy0R3402puFdGPtEvcFOuqbtORe0mWKMGNEYtt/o4D3hNXAFVAvg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.com; spf=pass smtp.mailfrom=gmail.com; arc=none smtp.client-ip=209.85.128.49 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-wm1-f49.google.com with SMTP id 5b1f17b1804b1-486fd5360d4so1569475e9.1 for ; Wed, 25 Mar 2026 10:24:52 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1774459489; x=1775064289; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:reply-to:user-agent:mime-version:date :message-id:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=wiw/GUjidliX10Xt88+2grOFSA9ojrEc+pd+AHSqD4Y=; b=ZvQUxzHZYegD9i52GgQiIGR/QSKAx+voJ1qoiMtuoulw5GqiAj1HnTrko3ATwMsqcj VfONeyEuGViF+QzSkcvCZWU9iMndOd0J4Mo3EyD5ZtSv0iqdaeEVDsGdb1y9fnHflj8e RojtbAcqKz6SYginhSfXMtF3E24KudAG0eExTdXNsatW6WiO8i2DtjvEiLAH7wWMWwCh GqQMG71cdN8igqiIk845z/LD7VJQMq/lmwHPO405pzUZpTyaaDrNzPl4MIXAVtYV3aDJ CeQmPvN6Lmgy4is+D7OxJenE5o+fPLoBTWAmcw9NwJsplSPFzgtx+FTmZoR6dlrNxRby QAMA== X-Forwarded-Encrypted: i=1; AJvYcCUX4ztG9rON41gc3WjdlytUieEURN0kMKJrVlo8R2eRmdWc2+9JJDh2w2Td01MdaI9XdPRjtToGT0fo6Es=@vger.kernel.org X-Gm-Message-State: AOJu0Yz/Q32RqgLsDLAzfKId04zwsaHrR1dcgCtRl2uE1nAe4tfyc9tL WFrlWSfXb485Lpv/Am2fX7CK/lpbL5RaT8too/N/kdMvEEYpD9FKGPBX X-Gm-Gg: ATEYQzy/keTlIs4JwSUc3WEneDGM5xy1wGIPHQWdvePdu47ZRLXkVZxh3tFmQ8MvWTz 4NjLjG4lqY2Zx22tge8yssB8KudRCHTDbFvBS3leidToQ+oOmRU/Y0bAlTsaiIUpGF2ayVa4ETd 5wqtfdGBo/IQ4JWwg/a32eiMfjEq0V2hKT6kOj6UqeLvpXwOu7SbIFBQG7fCONPJ8RpfWQNl4cT xlmfNxwwpXGLwP8a6PeHSs3x0bf2ayWugvK/nENhqk/b9sOkNXxVsdc4dpGGvvEISoYFqgp6czc 7/BpdYj779PNpB0EY6eJVNr4q6riau4IMXpnt0WX5IJD0QuIwDVMRh9Z+5M8VF8lRwcuWFJAQ3Y 2BrdR0tRWBirauQBLZrorg1K/V0xtJYHvvCBgNa2ZqrzKDpKCXYs2XNzDKqHK9W4YrfUYL6Dffs JLOXPOewJPHgwxO5fxtZk= X-Received: by 2002:a05:600c:4705:b0:485:a4de:f4f9 with SMTP id 5b1f17b1804b1-4871608406dmr70720405e9.27.1774459489238; Wed, 25 Mar 2026 10:24:49 -0700 (PDT) Received: from [0.0.0.0] ([94.156.174.93]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4871e5d195bsm8481415e9.3.2026.03.25.10.24.43 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 25 Mar 2026 10:24:48 -0700 (PDT) Message-ID: <76bba9e1-1e87-413e-94d7-80e7c352a55b@linux.com> Date: Wed, 25 Mar 2026 20:24:42 +0300 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Reply-To: alex.popov@linux.com Subject: Re: [PATCH] wifi: virt_wifi: remove SET_NETDEV_DEV to avoid use-after-free To: Andrew Lunn Cc: Jakub Kicinski , David Miller , Eric Dumazet , Paolo Abeni , Simon Horman , Maxime Chevallier , Michal Kubecek , Gal Pressman , Kory Maincent , Oleksij Rempel , Ido Schimmel , Heiner Kallweit , Greg KH , Johannes Berg , James Guan , Kees Cook , Paul Moses , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, security@kernel.org, notify@kernel.org References: <20260324224607.374327-1-alex.popov@linux.com> Content-Language: en-US From: Alexander Popov In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 3/25/26 15:34, Andrew Lunn wrote: > On Wed, Mar 25, 2026 at 01:46:02AM +0300, Alexander Popov wrote: >> Currently we execute `SET_NETDEV_DEV(dev, &priv->lowerdev->dev)` for >> the virt_wifi net devices. However, unregistering a virt_wifi device in >> netdev_run_todo() can happen together with the device referenced by >> SET_NETDEV_DEV(). >> >> It can result in use-after-free during the ethtool operations performed >> on a virt_wifi device that is currently being unregistered. Such a net >> device can have the `dev.parent` field pointing to the freed memory, >> but ethnl_ops_begin() calls `pm_runtime_get_sync(dev->dev.parent)`. >> >> Let's remove SET_NETDEV_DEV for virt_wifi to avoid bugs like this: > > Did you have a look at all user of SET_NETDEV_DEV() to see if there > are other examples of the same bug? > > What i found was: > > https://elixir.bootlin.com/linux/v6.19.9/source/drivers/net/ethernet/mellanox/mlx4/en_netdev.c#L3180 > > Does this have the same problem? Andrew, I can't say about this particular net device. Looks like it refers to a specific ethernet adapter. How can we distinguish security-relevant bugs similar to this use-after-free: an unprivileged user must be able to create a given net device via user namespaces. As I mentioned, applying this fix in ethtool could help against them: https://lore.kernel.org/all/20260322075917.254874-1-alex.popov@linux.com/T/#u Best regards, Alexander