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George Dunlap
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George Dunlap

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"It turns out that some of those attempts to clear sensitive information (like private keys) out of memory using memset() and bzero() were optimized away by some compilers. Clang/LLVM and GCC 5 use an optimization known as "dead store elimination" that gets rid of store operations to memory that is never read again."

It's incredible to me that with all the advancements in safety in languages as a whole, and in important warnings for "risky behavior" in gcc itself, that these sorts of compiler security bugs are still tolerated.

And bugs -- design bugs -- is what they are. If the OpenSSH team -- one of the most paranoid, security-focused teams on the planet -- can trip over it, nobody si safe. No 0.5% performance improvement is worth opening up this kind of massive security hole.
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George Dunlap

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Hmm, so apparently there's an update to Windows 2008 in which an updated virtio block driver from SuSE will replace the virtio block driver from RedHat, causing your VM not to be able to boot on RedHat systems any longer. 
Set Page Width: [ 80 ] [ 90 ] [ 100 ] [ 120 ]. Group: *BSD: aic7xxx appscript-changes appscript-dev bsdi-announce bsdi-users bsdinstaller-discussion calendarserver-changes calendarserver-dev calendarserver-users darwinbuild-changes darwinbuild-dev dragonfly-bugs dragonfly-commits dragonfly-docs ...
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George Dunlap

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"Despite the inherently functional character of all computer code, the Copyright Act makes clear that such code can be copyrightable. Nothing about the declaring code at issue here materially distinguishes it from other computer code, and petitioner has identified no genuine conflict of authority concerning Section 102(b)’s applicability to circumstances like these." -- the US DoJ simultaneously demonstrates the knowledge and ignorance about computer programming
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George Dunlap

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Spend all morning catching up on mail from xen-devel; finish just before lunch at 1pm.  By 3:30, 125 new unread messages. 
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CVE-2015-3456 ("Venom") and Xen: why are you vulnerable?
#xen   #xenproject   #venom

Let me spend a few words on CVE-2015-3456, also known as "Venom". Poor choice of a false acronym, if you ask me. 

The vulnerability is caused by a bug in the QEMU floppy drive emulator.

This is exactly the sort of bugs that we are trying to prevent in Xen Project, by limiting, when not avoiding entirely, device emulation. This is why Xen on ARM does not do any emulation at all. This is also why Xen on x86 still provides the ability to boot good old PV guests, which do not come with a large, exploitable, emulated environment.

If you are using Xen on ARM, you are OK. If you are using Xen on x86 with just PV guests or PVH guests (the new, faster, flavour of PV guests), you are also OK. If you are using HVM guests (builder="hvm" in the VM config file), you are affected.

As you probably know, Xen HVM guests rely on QEMU for emulation. Nonetheless we still try to limit the surface of attack, by disabling as many device emulators as possible by default.

For example we disable the floppy drive emulator.

Yes, you have heard correctly: the Xen toolstack disables a bunch of QEMU devices, including the floppy drive emulator, to avoid security vulnerabilities like "Venom".

So is Xen really vulnerable? Unfortunately yes, because of another QEMU bug: QEMU does not actually disable floppy drives, even when you ask nicely.

Sigh. Oh well, at least we tried. :-/
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George Dunlap

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Running into an issue at the "Installing recovery [something]" step.

I've got a Samsung Galaxy S2 (Intl) (GT-I9100) running Android 2.3.6, and a MacBook Air running the latest version of OSX.  Downloaded and installed the Android app, and the Mac beta installer.

Installer detected the device correctly and downloaded all the relevant images, then said something about installing a recovery image.  Phone to rebooted, and the screen has the Android logo and says "Downloading... Do not turn off target!!"  But at this point, the installer after waiting for a bit says, "We couldn't talk to your device."

I don't have another computer, and I don't have antivirus.  Clicking "try again" doesn't seem to help.

(Powering down the phone returns it to normal -- phew!)

I've tried this a couple different times now, and it has the same effect.

One thing I thought might be confounding things is that I do have the Android development kit installed, which has its own version of adb; and, the first time I tried this I had forgotten that I had Eclipse running in the other window.  But I get the same exact effect even after rebooting the whole system.

After getting to this state, there does seem to be an adb server running; but it seems to be the cm one, not the SDK one.  I killed the running one and ran "adb devices -l", and it didn't come up with anything; so it may indeed be that something is weird with the "downloading" mode that it doesn't talk to adb for some reason. 

Any ideas?  Would having the old version of Android (2.3.6) matter?

Thanks!
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Great -- I'll give that a try.  Thanks all!
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George Dunlap

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So simplifying a lot:  Ubuntu takes a radically community-oriented distro and puts some company-written "patches" on it.  CentOS SIGs take a completely company-written distro and puts some community "patches" on it.
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George Dunlap

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So the SFC is doing a fundraiser. According to their blog post [1], "We have structured the campaign with two make-or-break levels: a lower level that will just sustain the organization for a "bare minimum" service plan to our member projects, and a separate, higher level to continue doing copyleft enforcement. If we don't meet these goals we'll be forced to radically restructure."

Why this sudden need for funding? According to the same blog post, "...since we launched the VMware suit some of our corporate funding has been pulled because we tackle important but controversial issues, like GPL compliance. We have even have had talks blocked or cancelled at conferences."

They haven't named any names, but according to some clever sleuths [2], only two companies have recently dropped their SFC membership: a company called appendto.com (who appears to have been acquired by another company), and the Linux Foundation.

VMWare is a silver member of the Linux Foundation. [3]

[1] http://sfconservancy.org/blog/2015/nov/24/faif-carols-fundraiser/

[2] https://lwn.net/Articles/665855/

[3] http://www.linuxfoundation.org/about/members
The Software Freedom Conservancy provides a non-profit home and services to Free, Libre and Open Source Software (FLOSS) projects.
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George Dunlap

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"I do not want to be offensive.
I want to be helpful.
I believe this question needs to be asked."
[Haskell-cafe] how to make this work recursive ? Richard A. O'Keefe ok at cs.otago.ac.nz. Sun Mar 1 23:49:46 UTC 2015. Previous message: [Haskell-cafe] how to make this work recursive ? Next message: [Haskell-cafe] how to make this work recursive ? Messages sorted by: [ date ] [ thread ] ...
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George Dunlap

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gpg is really easy to use if you do things the one exact way the author thinks you should do it.  For instance, if you want to sign someone's key and then publish your signatures directly to the keyservers, three simple commands; easy peasy.

If you want to sign someone's key and then just send them the signature, for them to do with what they want -- time to write a complicated script that involves creating a fake gpg root and importing and exporting things half a dozen times.  Even that's a bit redundant, because it includes all his own subkeys and self-signatures.  If you want a really minimal signature, you have to start manually splitting the file into bits and re-assembling it...
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Well there shouldn't have to be a script. :-)  But as it turns out, I had tried caff (the Debian keysigning party thing) some time before and it just failed with a mysterious error.  After going back and trying it again recently, I think I understand why it didn't work -- gpg2  has a bug where the code that spawns the agent doesn't pass on alternate home directories properly.  So if your master key is anywhere other than in your home directory, and you have a passphrase on it (which of course you should), then it will fail.
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George Dunlap

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Oh what a tangled web we weave, when first we try to boot a modern x86 SMP system...
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'So to reiterate: LLVM was created because of GCC's deliberately non-modular, non-reusable architecture, and not because GCC was GPLed. ...I think the lesson we can all draw is that architectural decisions made for political strategy reasons are of limited utility. Eventually, code designed for technical superiority will become more popular than code with features missing for "strategic reasons".' 
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