From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BC6C71D47D9; Tue, 17 Dec 2024 12:38:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734439091; cv=none; b=MLIzu1BjizkzkFAhVS8C8dzz/KM9VgVsaod4im/hHDPa7kXHcCQuvYuSDsm97nGYZKaayrxd48bFKMjmReWDMT6l6t10KS91P25vbS2qT0rCbqNYvY6MzkpRxyA41jQT4q8KNrwvoX5QMuROmy2yJp3EnItKeHx1Zkr/Si+Tpto= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734439091; c=relaxed/simple; bh=PKeJ3zJJK1lWuXvjotJPwclyxHWk97zOS1saNeHsrAw=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=NC4+YCj57hYr/nwh8MH0Nv3rUvOllrVZQRtE3AhqK4uyP/LonbEtxlHiREfOC3MpPvsE4jgr58IfcGZpnAv2SAH+R8YM7JgWPkV3X1k5cMwbHsDbw4S7JPB0NffkFygBC7ZFk/OBdNFzXDlDbAOF+IQTE49FrSWqkDPgbTQqTrQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Iz0FwkVn; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Iz0FwkVn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E6E30C4CED3; Tue, 17 Dec 2024 12:38:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1734439091; bh=PKeJ3zJJK1lWuXvjotJPwclyxHWk97zOS1saNeHsrAw=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=Iz0FwkVn//6Gyd4X4RdFwtlJFM5LAODVSy58IbTVpAls7fAbVon9f0EqbWWmrkFQC WoMMF9LX3Wkt3S4A6uNnzY4J0CFctqZgMh9bp+p2mo+Iy/naz4PZTrckXMh621pQNA gieH53Hj4HJ55ecu5j12Ur3o3/PuKSz1Aw4mSUr0BiJvuBImIBbylIuSh+UetHTcaO 01jnRc68cJbMUXtt1t7DmjKyd2XJr15FkZGC42CkY3L/dFuOMRF0UBXuINJsfzm0DT MQK1dxio2Bc2/tEU1h2kEUl3Y/WPZjKkkTCBNcziTYTpxMVV5KwKjbEeD+f3HxosqZ bD/MqgIy3U1Cw== Message-ID: Date: Tue, 17 Dec 2024 13:38:05 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [Bug] Deadlock between rfkill_fop_write() and nfc_unregister_device() To: Johannes Berg , Sam Sun Cc: linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, Simon Horman , pabeni@redhat.com, kuba@kernel.org, Eric Dumazet , davem@davemloft.net References: <70f796f623a67b283c4fe3a1b56e59647a39ce6c.camel@sipsolutions.net> From: Krzysztof Kozlowski Content-Language: en-US Autocrypt: addr=krzk@kernel.org; keydata= xsFNBFVDQq4BEAC6KeLOfFsAvFMBsrCrJ2bCalhPv5+KQF2PS2+iwZI8BpRZoV+Bd5kWvN79 cFgcqTTuNHjAvxtUG8pQgGTHAObYs6xeYJtjUH0ZX6ndJ33FJYf5V3yXqqjcZ30FgHzJCFUu JMp7PSyMPzpUXfU12yfcRYVEMQrmplNZssmYhiTeVicuOOypWugZKVLGNm0IweVCaZ/DJDIH gNbpvVwjcKYrx85m9cBVEBUGaQP6AT7qlVCkrf50v8bofSIyVa2xmubbAwwFA1oxoOusjPIE J3iadrwpFvsZjF5uHAKS+7wHLoW9hVzOnLbX6ajk5Hf8Pb1m+VH/E8bPBNNYKkfTtypTDUCj NYcd27tjnXfG+SDs/EXNUAIRefCyvaRG7oRYF3Ec+2RgQDRnmmjCjoQNbFrJvJkFHlPeHaeS BosGY+XWKydnmsfY7SSnjAzLUGAFhLd/XDVpb1Een2XucPpKvt9ORF+48gy12FA5GduRLhQU vK4tU7ojoem/G23PcowM1CwPurC8sAVsQb9KmwTGh7rVz3ks3w/zfGBy3+WmLg++C2Wct6nM Pd8/6CBVjEWqD06/RjI2AnjIq5fSEH/BIfXXfC68nMp9BZoy3So4ZsbOlBmtAPvMYX6U8VwD TNeBxJu5Ex0Izf1NV9CzC3nNaFUYOY8KfN01X5SExAoVTr09ewARAQABzSVLcnp5c3p0b2Yg S296bG93c2tpIDxrcnprQGtlcm5lbC5vcmc+wsGVBBMBCgA/AhsDBgsJCAcDAgYVCAIJCgsE FgIDAQIeAQIXgBYhBJvQfg4MUfjVlne3VBuTQ307QWKbBQJgPO8PBQkUX63hAAoJEBuTQ307 QWKbBn8P+QFxwl7pDsAKR1InemMAmuykCHl+XgC0LDqrsWhAH5TYeTVXGSyDsuZjHvj+FRP+ gZaEIYSw2Yf0e91U9HXo3RYhEwSmxUQ4Fjhc9qAwGKVPQf6YuQ5yy6pzI8brcKmHHOGrB3tP /MODPt81M1zpograAC2WTDzkICfHKj8LpXp45PylD99J9q0Y+gb04CG5/wXs+1hJy/dz0tYy iua4nCuSRbxnSHKBS5vvjosWWjWQXsRKd+zzXp6kfRHHpzJkhRwF6ArXi4XnQ+REnoTfM5Fk VmVmSQ3yFKKePEzoIriT1b2sXO0g5QXOAvFqB65LZjXG9jGJoVG6ZJrUV1MVK8vamKoVbUEe 0NlLl/tX96HLowHHoKhxEsbFzGzKiFLh7hyboTpy2whdonkDxpnv/H8wE9M3VW/fPgnL2nPe xaBLqyHxy9hA9JrZvxg3IQ61x7rtBWBUQPmEaK0azW+l3ysiNpBhISkZrsW3ZUdknWu87nh6 eTB7mR7xBcVxnomxWwJI4B0wuMwCPdgbV6YDUKCuSgRMUEiVry10xd9KLypR9Vfyn1AhROrq AubRPVeJBf9zR5UW1trJNfwVt3XmbHX50HCcHdEdCKiT9O+FiEcahIaWh9lihvO0ci0TtVGZ MCEtaCE80Q3Ma9RdHYB3uVF930jwquplFLNF+IBCn5JRzsFNBFVDXDQBEADNkrQYSREUL4D3 Gws46JEoZ9HEQOKtkrwjrzlw/tCmqVzERRPvz2Xg8n7+HRCrgqnodIYoUh5WsU84N03KlLue MNsWLJBvBaubYN4JuJIdRr4dS4oyF1/fQAQPHh8Thpiz0SAZFx6iWKB7Qrz3OrGCjTPcW6ei OMheesVS5hxietSmlin+SilmIAPZHx7n242u6kdHOh+/SyLImKn/dh9RzatVpUKbv34eP1wA GldWsRxbf3WP9pFNObSzI/Bo3kA89Xx2rO2roC+Gq4LeHvo7ptzcLcrqaHUAcZ3CgFG88CnA 6z6lBZn0WyewEcPOPdcUB2Q7D/NiUY+HDiV99rAYPJztjeTrBSTnHeSBPb+qn5ZZGQwIdUW9 YegxWKvXXHTwB5eMzo/RB6vffwqcnHDoe0q7VgzRRZJwpi6aMIXLfeWZ5Wrwaw2zldFuO4Dt 91pFzBSOIpeMtfgb/Pfe/a1WJ/GgaIRIBE+NUqckM+3zJHGmVPqJP/h2Iwv6nw8U+7Yyl6gU BLHFTg2hYnLFJI4Xjg+AX1hHFVKmvl3VBHIsBv0oDcsQWXqY+NaFahT0lRPjYtrTa1v3tem/ JoFzZ4B0p27K+qQCF2R96hVvuEyjzBmdq2esyE6zIqftdo4MOJho8uctOiWbwNNq2U9pPWmu 4vXVFBYIGmpyNPYzRm0QPwARAQABwsF8BBgBCgAmAhsMFiEEm9B+DgxR+NWWd7dUG5NDfTtB YpsFAmA872oFCRRflLYACgkQG5NDfTtBYpvScw/9GrqBrVLuJoJ52qBBKUBDo4E+5fU1bjt0 Gv0nh/hNJuecuRY6aemU6HOPNc2t8QHMSvwbSF+Vp9ZkOvrM36yUOufctoqON+wXrliEY0J4 ksR89ZILRRAold9Mh0YDqEJc1HmuxYLJ7lnbLYH1oui8bLbMBM8S2Uo9RKqV2GROLi44enVt vdrDvo+CxKj2K+d4cleCNiz5qbTxPUW/cgkwG0lJc4I4sso7l4XMDKn95c7JtNsuzqKvhEVS oic5by3fbUnuI0cemeizF4QdtX2uQxrP7RwHFBd+YUia7zCcz0//rv6FZmAxWZGy5arNl6Vm lQqNo7/Poh8WWfRS+xegBxc6hBXahpyUKphAKYkah+m+I0QToCfnGKnPqyYIMDEHCS/RfqA5 t8F+O56+oyLBAeWX7XcmyM6TGeVfb+OZVMJnZzK0s2VYAuI0Rl87FBFYgULdgqKV7R7WHzwD uZwJCLykjad45hsWcOGk3OcaAGQS6NDlfhM6O9aYNwGL6tGt/6BkRikNOs7VDEa4/HlbaSJo 7FgndGw1kWmkeL6oQh7wBvYll2buKod4qYntmNKEicoHGU+x91Gcan8mCoqhJkbqrL7+nXG2 5Q/GS5M9RFWS+nYyJh+c3OcfKqVcZQNANItt7+ULzdNJuhvTRRdC3g9hmCEuNSr+CLMdnRBY fv0= In-Reply-To: <70f796f623a67b283c4fe3a1b56e59647a39ce6c.camel@sipsolutions.net> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 17/12/2024 13:09, Johannes Berg wrote: > On Tue, 2024-12-17 at 20:01 +0800, Sam Sun wrote: >> On Tue, Dec 17, 2024 at 7:33 PM Johannes Berg wrote: >>> >>> On Tue, 2024-12-17 at 11:46 +0100, Johannes Berg wrote: >>>> On Tue, 2024-12-17 at 17:33 +0800, Sam Sun wrote: >>>>> Dear developers and maintainers, >>>>> >>>>> We originally encountered a task hung while using our modified >>>>> syzkaller. It was tested against the latest upstream kernel. We >>>>> analyzed the root cause and pinpoint the kernel crash log to the >>>>> following two tasks. >>>>> >>>> >>>> This issue has been known a very long time and should be fixed in NFC, >>>> but I guess nobody is around to do it. >>>> >>>> https://syzkaller.appspot.com/bug?extid=bb540a4bbfb4ae3b425d >>>> >>> >>> I think this one is also the same: >>> >>> https://syzkaller.appspot.com/bug?extid=9ef743bba3a17c756174 >>> >>> and that's much older still. >>> >> >> Thanks for your quick reply! I am sorry that I didn't double-check the >> call stack of historical bugs reported by Syzbot. I will be careful >> next time. >> > > No worries. Maybe someone who feels responsible for NFC will wake up ;-) Patches are welcomed. The NFC stack was full of deadlocks, races and uses-after-free. The only consolation was that all of them were triggered by the virtual device driver, not real world cases. Many syzkaller reports were eventually fixed, but I guess many are still open. If anyone wants to take the responsibility for NFC in terms of actually developing and fixes the stack, go ahead, because I have time here only for reviews (and these are still behind netdev timeframe expectations). Best regards, Krzysztof