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 B94E41632EF; Sat, 21 Dec 2024 20:11:24 +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=1734811884; cv=none; b=qh0b5oMecCv3e+y5IFK2H/lFkAwMbKN8nUucHmXCwGIBoIJ/ZcYGJvy9yFYBFJcEy4WTi2UlrPWwQ4b5L4f/wFznqLgGzxy0LNhoWxIsTp28XZsYt2VkOpVxwgIUXlyC5Pd3fQwFfdUjs5j3bYkh8qLP6iJ5QGZPp9OBDkXOp34= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734811884; c=relaxed/simple; bh=S2zKPTDu6zm54vR7ChtvutkcPZm7paeJy7waA6uaSGM=; h=Mime-Version:Content-Type:Date:Message-Id:Cc:Subject:From:To: References:In-Reply-To; b=AEu143QNaO8AAGkH6BMZvGtU+A51hObZ1I3vOWgjrTxqDSxl970UdEV4griSVXBDHJpryZ6AJavGElBzJ7CSpKcocEK6JdNbnXg6ASvOG8tqeOBXNXWmQjOSC82vmd9R6HQ8/59l7ngULE0Uwx7mD1tlDVi744LyYCzRWwhh1/w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id B484DC4CECE; Sat, 21 Dec 2024 20:11:23 +0000 (UTC) Precedence: bulk X-Mailing-List: linux-integrity@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Sat, 21 Dec 2024 22:11:20 +0200 Message-Id: Cc: , "Peter Huewe" , "Jason Gunthorpe" , "Colin Ian King" , "Joe Hattori" , "Stefan Berger" , "Roberto Sassu" , "Al Viro" , "Andy Liang" , "Matthew Garrett" , "Mimi Zohar" , Subject: Re: [PATCH] tpm: Map the ACPI provided event log From: "Jarkko Sakkinen" To: "James Bottomley" , "Ard Biesheuvel" , "Jarkko Sakkinen" X-Mailer: aerc 0.18.2 References: <20241221113318.562138-1-jarkko@kernel.org> In-Reply-To: On Sat Dec 21, 2024 at 7:16 PM EET, James Bottomley wrote: > On Sat, 2024-12-21 at 17:04 +0100, Ard Biesheuvel wrote: > > On Sat, 21 Dec 2024 at 12:33, Jarkko Sakkinen > > wrote: > > >=20 > > > The following failure was reported: > > >=20 > > > [=C2=A0=C2=A0 10.693310][=C2=A0=C2=A0=C2=A0 T1] tpm_tis STM0925:00: 2= .0 TPM (device-id 0x3, > > > rev-id 0) > > > [=C2=A0=C2=A0 10.848132][=C2=A0=C2=A0=C2=A0 T1] ------------[ cut her= e ]------------ > > > [=C2=A0=C2=A0 10.853559][=C2=A0=C2=A0=C2=A0 T1] WARNING: CPU: 59 PID:= 1 at > > > mm/page_alloc.c:4727 __alloc_pages_noprof+0x2ca/0x330 > > > [=C2=A0=C2=A0 10.862827][=C2=A0=C2=A0=C2=A0 T1] Modules linked in: > > > [=C2=A0=C2=A0 10.866671][=C2=A0=C2=A0=C2=A0 T1] CPU: 59 UID: 0 PID: 1= Comm: swapper/0 Not > > > tainted 6.12.0-lp155.2.g52785e2-default #1 openSUSE Tumbleweed > > > (unreleased) 588cd98293a7c9eba9013378d807364c088c9375 > > > [=C2=A0=C2=A0 10.882741][=C2=A0=C2=A0=C2=A0 T1] Hardware name: HPE Pr= oLiant DL320 > > > Gen12/ProLiant DL320 Gen12, BIOS 1.20 10/28/2024 > > > [=C2=A0=C2=A0 10.892170][=C2=A0=C2=A0=C2=A0 T1] RIP: 0010:__alloc_pag= es_noprof+0x2ca/0x330 > > > [=C2=A0=C2=A0 10.898103][=C2=A0=C2=A0=C2=A0 T1] Code: 24 08 e9 4a fe = ff ff e8 34 36 fa ff e9 > > > 88 fe ff ff 83 fe 0a 0f 86 b3 fd ff ff 80 3d 01 e7 ce 01 00 75 09 > > > c6 05 f8 e6 ce 01 01 <0f> 0b 45 31 ff e9 e5 fe ff ff f7 c2 00 00 08 > > > 00 75 42 89 d9 80 e1 > > > [=C2=A0=C2=A0 10.917750][=C2=A0=C2=A0=C2=A0 T1] RSP: 0000:ffffb7cf400= 77980 EFLAGS: 00010246 > > > [=C2=A0=C2=A0 10.923777][=C2=A0=C2=A0=C2=A0 T1] RAX: 0000000000000000= RBX: 0000000000040cc0 > > > RCX: 0000000000000000 > > > [=C2=A0=C2=A0 10.931727][=C2=A0=C2=A0=C2=A0 T1] RDX: 0000000000000000= RSI: 000000000000000c > > > RDI: 0000000000040cc0 > > >=20 > > > Above shows that ACPI pointed a 16 MiB buffer for the log events > > > because RSI maps to the 'order' parameter of > > > __alloc_pages_noprof(). Address the bug by mapping the region when > > > needed instead of copying. > > >=20 > > > Reported-by: Andy Liang > > > Closes: https://bugzilla.kernel.org/show_bug.cgi?id=3D219495 > > > Suggested-by: Matthew Garrett > > > Signed-off-by: Jarkko Sakkinen > >=20 > > This is a very intrusive fix - care to provide some more context on > > why all these changes are needed? > > Since the bug reports never found an actual log over a few tens of > kilobytes this is caused by the BIOS implementation allocating a huge > buffer that is mostly unused. > > There are two other possibilities for fixing this, which were both part > of the original suggestions. One would be to work out the size of the > log and then allocate an exact size. This would require implementing > tpm1 and tpm2 parsers for log size. However, since we can never go > over KMALLOC_MAX_SIZE without an error even with this calculated size, > the simplest straight line fix would be to cap the copy at > KMALLOC_MAX_SIZE if it's over. That would be a simple one liner. All I'm saying is this. I've got bunch of complains of this from mainly SUSE, and now I'm here with a response to that feedback. So I don't care. You decide. I'm 100% sure that the fix that Stefan proposed is not a sustainable path in long-term, so I guess this was more like more long-term but intrusive fix. Ya, and also please test the changes, especially anything that can reach of OF eventlogs would be welcome feedback. BR, Jarkko