From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from the.earth.li (the.earth.li [93.93.131.124]) (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 485511D0DCE; Wed, 2 Oct 2024 19:26:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=93.93.131.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727897211; cv=none; b=EVXGO3YeEoAPd97ybRDjAHth48s54JiBNRqmQhwl4JElyidwWrc/BfgC1RLeYEcYTHMpB8AFudqBwQdJP8CUfvxByDoYYIqApaxF8F2nDHaURkH3qpUAG0LfE9+LpOhR980gN81gdvCrgPmG0xljPUWgybvYCbDDa9MRs5TGCas= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727897211; c=relaxed/simple; bh=FAi/yaWlzEaGZY94Cy0xf1w9t3bJECdggONxw7jhmLM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=NlDr21wn/x29RTCr43vRxq59XmdA6TCerj+OM7DkyMG6KePQicevFD+sO0AO+IEHfGwnJzfMyy1IdH5AHHzAgLRMo13dudd9k4GSsNgHexhy2nm3C9CIRIdB6bq46Gu2a9PAjiv3MJQdyWC53ch9N+hYNv9iAEm9taOQeoiy6CI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=earth.li; spf=pass smtp.mailfrom=earth.li; dkim=pass (2048-bit key) header.d=earth.li header.i=@earth.li header.b=vOK8DXVy; arc=none smtp.client-ip=93.93.131.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=earth.li Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=earth.li Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=earth.li header.i=@earth.li header.b="vOK8DXVy" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=earth.li; s=the; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID:Subject: Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=3CUqPSRPJx6WKMwitN1e//58gfK5Iq+dhEFVNJ9G8Fg=; b=vOK8DXVyukL1SLX2p/PNGNasUS oIzkk3ttq09LQIj4S46N2RnfzETclar6N6pqMKkw1WLoiqzCpd3nG3HPB9qzQN4KWufm10TzrGPUS AHZArfO7Qx4c2EvVXu65uWFoa9OVt0MfhKjith61tC6gvzIJkwowm6Pd1cGPH2i5UUTB7ZC53Xz/C NiBuctz5YnSbUg9M3s84pc6kGGReHRnIWFaSoroeaAm1hRuDiUmxWsJeZ25I0tuHxvjGQHtWFBV4w ikW2HgrdXuwI5xfRvogYZVnzHjv3dSGQm+KCMgsfz9kO5QMvM1EJRrNyvk7vhoLcJxRyoX7RaLbW6 dFBLn8uw==; Received: from noodles by the.earth.li with local (Exim 4.96) (envelope-from ) id 1sw4zk-00DLm2-0H; Wed, 02 Oct 2024 20:26:44 +0100 Date: Wed, 2 Oct 2024 20:26:44 +0100 From: Jonathan McDowell To: James Bottomley Cc: linux-integrity@vger.kernel.org, Jarkko Sakkinen , Peter Huewe , Jason Gunthorpe , linux-kernel@vger.kernel.org Subject: Re: Problems with TPM timeouts Message-ID: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Wed, Oct 02, 2024 at 10:31:34AM -0700, James Bottomley wrote: > On Wed, 2024-10-02 at 18:03 +0100, Jonathan McDowell wrote: > [...] > > First, I've seen James' post extending the TPM timeouts back in 2018 > > ( > > https://lore.kernel.org/linux-integrity/1531329074.3260.9.camel@Hansen > > Partnership.com/), which doesn't seem to have been picked up. Was an > > alternative resolution found, or are you still using this, James? > > No, because I've got a newer laptop. The problem was seen on a 2015 > XPS-13 with a Nuvoton TPM that was software upgraded to 2.0 (and had > several other problems because of this). I assumed, based on the lack > of reports from others, that this was a problem specific to my TPM and > so didn't push it. Yes, there's somewhat a lack of reports of TPM issues but I can't tell if that's because people aren't using them in anger, or if they're just not having any issues. This is seen across thousands of machines, so it's not a specific TPM issue. > The annoying thing for me was that the TPM didn't seem to recover. > Once it started giving timeouts it carried on timing out until machine > reset, which really caused problems because all my keys are TPM > resident. > > Is yours a permanent problem like mine, or is it transient (TPM > recovers and comes back)? Ah. So the problem I've described is transient; we get a timeout, that sometimes causes problems (e.g. the transient space leakage I've previously sent a patch for), but ultimately the TPM responds just fine next time. We _do_ have a separate issue where the TPM returns 0xFFFF for STS, the kernel does the "invalid TPM_STS.x" with stack thing, then the TPM never responds to a command again until a machine reboot. However in that instance it _does_ still respond to reading the TPM_DID_VID register, and allowing entering/leaving locality, so that looks like it's firmly a TPM problem of some sort. J. -- /-\ | No thanks, I'm already having one. |@/ Debian GNU/Linux Developer | \- |