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From: Jarkko Sakkinen <jarkko.sakkinen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
To: Petr Vandrovec <petr-pghWNbHTmq7QT0dZR+AlfA@public.gmane.org>
Cc: tpmdd-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org
Subject: Re: [PATCH 4/4] Improve handling of TPM2 event logs
Date: Thu, 6 Apr 2017 09:45:34 +0300	[thread overview]
Message-ID: <20170406064534.yrx7r5kteavog2wr@intel.com> (raw)
In-Reply-To: <20170406064454.mwb52hnl54tqxss2-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>

On Thu, Apr 06, 2017 at 09:44:54AM +0300, Jarkko Sakkinen wrote:
> On Thu, Apr 06, 2017 at 09:35:34AM +0300, Jarkko Sakkinen wrote:
> > On Wed, Apr 05, 2017 at 01:29:29PM -0700, Petr Vandrovec wrote:
> > > Jarkko Sakkinen wrote:
> > > > On Wed, Mar 29, 2017 at 12:43:30AM -0700, Petr Vandrovec wrote:
> > > > > From: Petr Vandrovec<petr-pghWNbHTmq7QT0dZR+AlfA@public.gmane.org>
> > > > > 
> > > > > When TPM2 log has entries with more than 3 digests, or with digests
> > > > > not listed in the log header, log gets misparsed, eventually
> > > > > leading to kernel complaint that code tried to vmalloc 512MB of
> > > > > memory (I have no idea what would happen on bigger system).
> > > > 
> > > > It would be easier to follow this if you would give a concrete
> > > > example of such situation. Since you are contributing this, you
> > > > must must have bumped into this, haven't you?
> > > 
> > > Yes.  Our firmware reports TPM2 log with 4 digests (SHA1, SHA256, SHA384,
> > > SHA512).  Current code in kernel skips over first 3 digests only, trying to
> > > parse 4th digest as event length, coming to conclusion that entry is hundred
> > > of megabytes or few gigabytes long, and then failing to vmalloc() that
> > > amount of memory.
> > > 
> > > You can find parsed textual log at
> > > https://drive.google.com/open?id=0B7WL11GSMhrQRDBLWjc3bEZQTEk (192KB), and
> > > binary log at https://drive.google.com/open?id=0B7WL11GSMhrQQ1RCMmRmM2paR3c
> > > (48KB).
> > > 
> > > I hit situation with malformed event log on my Dell laptop - after TPM
> > > firmware got updated from 1.2 to 2.0, chip & everything is reported as TPM2,
> > > except that log stays in TPM1.2 format.
> > 
> > Great thank you. I think I'll merge this already to my master branch
> > (not yet the whole series). Thanks a lot for spotting and fixing this
> > regression.
> > 
> > /Jarkko 
> 
> http://git.infradead.org/users/jjs/linux-tpmdd.git/commit/21229f46ce976bb8652d1da55f7823f4818b06d7
> 
> Please consider following in the future:
> 
> - Short summary was misleading. It should fix loud and clear as
>   it fixes a real regression. It should not be called an improvement.
> - Add the fixes line.
> - I would recommend to submit fixes separately from rest of the series
>   so that they get more quickly noticed.
> 
> This will make both your and my life easier...
> 
> /Jarkko

And please run checkpatch:

WARNING: line over 80 characters
#61: FILE: drivers/char/tpm/tpm2_eventlog.c:69:
+				marker +=
efispecid->digest_sizes[j].digest_size;

/Jarkko

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      parent reply	other threads:[~2017-04-06  6:45 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-29  7:43 [PATCH 4/4] Improve handling of TPM2 event logs Petr Vandrovec
     [not found] ` <20170329074330.b2rbsbt2zc7o22q7-WbvboCQVrrgDIl+Cyo8nDyLysJ1jNyTM@public.gmane.org>
2017-04-05 11:46   ` Jarkko Sakkinen
     [not found]     ` <20170405114650.c2kkkz2th2emalcc-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2017-04-05 20:29       ` Petr Vandrovec
     [not found]         ` <58E553A9.8010804-pghWNbHTmq7QT0dZR+AlfA@public.gmane.org>
2017-04-06  6:35           ` Jarkko Sakkinen
     [not found]             ` <20170406063534.nw33ck7gek7g4vur-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2017-04-06  6:44               ` Jarkko Sakkinen
     [not found]                 ` <20170406064454.mwb52hnl54tqxss2-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2017-04-06  6:45                   ` Jarkko Sakkinen [this message]

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