From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sipsolutions.net (s3.sipsolutions.net [168.119.38.16]) (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 AD9CE1E5708; Tue, 17 Dec 2024 12:09:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=168.119.38.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734437389; cv=none; b=tH1PJN/QySpnb5NrVjfqwK09fLwc1is2qr50BwBzXdomctDqwpnO8R988yvtiyv1aOG7IV0nLOxXVmrkbtL27o2MN0BVChGooaOytxtkPa5cPuEH78lj7VaX9p81gJtG3vbTK7rC1n/y2IXV+Iq3iyuQFv56ROu0HcgdsBEJrME= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734437389; c=relaxed/simple; bh=/SG3AzAHOff+hccD3OcucAh5OThZTC7Mgq9xZD7ruxo=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=HVVGndGlEZKrMpJv9OjjYWzZUmrkJ6sAU5oMhNNeep/KyRqtKm/jPzm6vJPTljrIDYXK7Qkqal975O15Zo2nTZ+gU7IMhP7+HKtTABdmCOXoDUoyMIDJtJIky0g9Tu2sc9WrVJtkvsOlRBkXWIQnpCwXl2DdaHk6Xw+dwDe39X4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sipsolutions.net; spf=pass smtp.mailfrom=sipsolutions.net; dkim=pass (2048-bit key) header.d=sipsolutions.net header.i=@sipsolutions.net header.b=pNQCeYb8; arc=none smtp.client-ip=168.119.38.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sipsolutions.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sipsolutions.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sipsolutions.net header.i=@sipsolutions.net header.b="pNQCeYb8" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sipsolutions.net; s=mail; h=MIME-Version:Content-Transfer-Encoding: Content-Type:References:In-Reply-To:Date:Cc:To:From:Subject:Message-ID:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-To: Resent-Cc:Resent-Message-ID; bh=/SG3AzAHOff+hccD3OcucAh5OThZTC7Mgq9xZD7ruxo=; t=1734437387; x=1735646987; b=pNQCeYb83bndxl855f4uqARs9WCSwk/EO1DiZMYjKFFCzkh /yFNBKAw/VBS84dA5tpLBMsmQeQBmSA4iC5CxV9hVsP0ylxLG4scE4pa7/Bk9K9jXRWJnWw0lVpR1 wVrO/9lzw/n0LLJujUghScnQY1xBq64E6EQyPCFPnDPvO3mVs+fDQjRkweps+ACOqWncOEeOIeDOp wWidTDmDJuV74Rq+QhG2vYwQbMXDmqKgy4BCJQUfI3zvv8YkCHMITbzLsx6PLWVXl5mdu5o73LYOk 8PFylKxK5pJ4PxAN3Sicxs2tBg9XnUzJcK/m2aMZLG4izNQ74BHXQXpBuYuQX8rA==; Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.98) (envelope-from ) id 1tNWOW-000000027FC-06Rs; Tue, 17 Dec 2024 13:09:44 +0100 Message-ID: <70f796f623a67b283c4fe3a1b56e59647a39ce6c.camel@sipsolutions.net> Subject: Re: [Bug] Deadlock between rfkill_fop_write() and nfc_unregister_device() From: Johannes Berg To: 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, krzk@kernel.org Date: Tue, 17 Dec 2024 13:09:42 +0100 In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.54.2 (3.54.2-1.fc41) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-malware-bazaar: not-scanned On Tue, 2024-12-17 at 20:01 +0800, Sam Sun wrote: > On Tue, Dec 17, 2024 at 7:33=E2=80=AFPM Johannes Berg wrote: > >=20 > > 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, > > > >=20 > > > > 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. > > > >=20 > > >=20 > > > This issue has been known a very long time and should be fixed in NFC= , > > > but I guess nobody is around to do it. > > >=20 > > > https://syzkaller.appspot.com/bug?extid=3Dbb540a4bbfb4ae3b425d > > >=20 > >=20 > > I think this one is also the same: > >=20 > > https://syzkaller.appspot.com/bug?extid=3D9ef743bba3a17c756174 > >=20 > > and that's much older still. > >=20 >=20 > 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. >=20 No worries. Maybe someone who feels responsible for NFC will wake up ;-) johannes