Date: Wed, 22 Oct 2014 12:09:57 +1100 From: Dewayne Geraghty <dewayne.geraghty@heuristicsystems.com.au> To: Hans Petter Selasky <hps@selasky.org> Cc: freebsd-security@freebsd.org, freebsd-usb@freebsd.org Subject: Re: BadUSB - On Accessories that Turn Evil, by Karsten Nohl + Jakob Lell Message-ID: <544703E5.7000007@heuristicsystems.com.au> In-Reply-To: <54369F43.9010806@selasky.org> References: <201410082347.s98NkjW3025396@fire.js.berklix.net> <54362AE2.90501@selasky.org> <CAPjTQNHbh40oeeuJnCk%2BiiKLOFO9TJU0Z13uRp6FawuUrmHvnw@mail.gmail.com> <54369F43.9010806@selasky.org>
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On 10/10/2014 1:44 AM, Hans Petter Selasky wrote: > On 10/09/14 15:59, Oliver Pinter wrote: >> On 10/9/14, Hans Petter Selasky <hps@selasky.org> wrote: >>> Hi Julian, >>> >>> On 10/09/14 01:46, Julian H. Stacey wrote: >>>> Hi Hans etc >>>> "Julian H. Stacey" wrote: >>>>> Hans Petter Selasky wrote: >>>>>> Hi, >>>>>> >>>>>> Can you test the following kernel patch and give some feedback: >>>>>> >>>>>> https://svnweb.freebsd.org/changeset/base/272733 >>>> >>>> I'm now on latest current with src & sys/ GENERIC >>>> /usr/src/.ctm_status # src-cur 11645 >>>> >>>> This time I downloaded your files properly >>>> (last time I was severely distracted & made a silly mistake) >>>> >>>>>> After the patch you will get something like: >>>>>> hw.usb.disable_enumeration: 0 >>>>>> dev.uhub.0.disable_enumeration: 0 >>>>>> dev.uhub.1.disable_enumeration: 0 >>>>>> ... >>>> >>>> sysctl -a | grep enumeration >>>> hw.usb.disable_enumeration: 0 >>>> dev.uhub.0.disable_enumeration: 0 >>>> dev.uhub.1.disable_enumeration: 0 >>>> dev.uhub.2.disable_enumeration: 0 >>>> dev.uhub.3.disable_enumeration: 0 >>>> dev.uhub.4.disable_enumeration: 0 >>>> >>>> sysctl -d hw.usb.disable_enumeration >>>> hw.usb.disable_enumeration: Set to disable all USB device >>>> enumeration. >>>> >>>> sysctl -d dev.uhub.4.disable_enumeration >>>> dev.uhub.4.disable_enumeration: Set to disable enumeration on >>>> this USB >>>> HUB. >>>> >>>> usbconfig >>>> ugen0.1: <EHCI root HUB Intel> at usbus0, cfg=0 md=HOST spd=HIGH >>>> (480Mbps) >>>> pwr=SAVE (0mA) >>>> ugen1.1: <EHCI root HUB Intel> at usbus1, cfg=0 md=HOST spd=HIGH >>>> (480Mbps) >>>> pwr=SAVE (0mA) >>>> ugen0.2: <product 0x0020 vendor 0x8087> at usbus0, cfg=0 md=HOST >>>> spd=HIGH >>>> (480Mbps) pwr=SAVE (0mA) >>>> ugen1.2: <product 0x0020 vendor 0x8087> at usbus1, cfg=0 md=HOST >>>> spd=HIGH >>>> (480Mbps) pwr=SAVE (0mA) >>>> ugen0.3: <1.3M WebCam XPA2535XY> at usbus0, cfg=255 md=HOST spd=HIGH >>>> (480Mbps) pwr=OFF (500mA) >>>> ugen1.3: <Semi Tech PS2 Keyboard - PS2 Mouse Semi Tech> at usbus1, >>>> cfg=0 >>>> md=HOST spd=LOW (1.5Mbps) pwr=ON (100mA) >>>> ugen1.4: <USB2.0 Hub vendor 0x05e3> at usbus1, cfg=0 md=HOST spd=HIGH >>>> (480Mbps) pwr=SAVE (100mA) >>>> >>> >>>> >>>> Great ! Seems to work. >>>> >>>> (Though I need to read up on how major & minor of ugen relate to >>>> the digit in eg 4.disable_enumeration) >>>> >>>> >>>>>> which is also settable through /boot/loader.conf (tunable) >>>> >>>> Good, >>>> I hope/presume loader.conf gets run before any USB, cos I recall >>>> lecturer Karsten Nohl pointing out one could get BadUSB taking up >>>> residence in USB controller chips inside a PC, ie for a built in >>>> mouse or web cam, so one would need to turn off enumeration earlier >>>> than when first external USB approaches to connect. >>> >>> Yes, if set by the loader.conf, you will only see the RootHUB after >>> boot. >>> >>> To get devices back after enabling enumeration again, you will need to >>> reset the HUBs: >>> >>> usbconfig -d X.1 reset >>> >>> For example. >>> >>> BTW: I've added some exceptions, that existing devices can be detached, >>> suspend/resumed and reset while the enumeration is disabled. >> >> Can we somehow improve this change, to powering down the ports/hubs >> which has the enumeration disabled? >> > > Hi, > > I've added this as an orthogonal feature. Please test and report back: > > hw.usb.disable_enumeration: 0 > hw.usb.disable_port_power: 0 > > dev.uhub.0.disable_enumeration: 0 > dev.uhub.0.disable_port_power: 0 > > https://svnweb.freebsd.org/changeset/base/272822 > > Thank you! > > --HPS > > _______________________________________________ > freebsd-usb@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-usb > To unsubscribe, send any mail to "freebsd-usb-unsubscribe@freebsd.org" > Hans, Thank-you for these enhancements, as its good to have something in the armoury to try to address this issue. I applied the patch https://lists.freebsd.org/pipermail/svn-src-head/2014-October/063443.html to an updated 10.Stable overnight. Disabling enumeration works as described above except that, placing the following in loader.conf has no effect? --- tail of /boot/loader.conf --- # 20141022 Didn't work as expected #dev.uhub.0.disable_enumeration="1" #dev.uhub.1.disable_enumeration="1" #dev.uhub.2.disable_enumeration="1" #dev.uhub.3.disable_enumeration="1" #dev.uhub.4.disable_enumeration="1" # 20141022 Also didn't work hw.usb.disable_enumeration="1" --- end of /boot/loader.conf --- I confirmed the setting was correctly read by loader, by interrupting the boot and showing the variables. But immediately after booting, sysctl -a|grep enumer hw.usb.disable_enumeration: 0 dev.uhub.0.disable_enumeration: 0 dev.uhub.1.disable_enumeration: 0 dev.uhub.2.disable_enumeration: 0 dev.uhub.3.disable_enumeration: 0 dev.uhub.4.disable_enumeration: 0 Any ideas why loader.conf settings weren't applied? They are applied via /etc/sysctl.conf, but by that stage, any harm has been done. It was interesting doing "user testing" (ie dumb things). Having a mouse in hub-unit.endpoint=0.2 sysctl dev.uhub.0.disable_enumeration=1 usbconfig -d 0.2 power_off provides an opportunity to make a fresh cup of tea... ;) Regards, Dewayne. -- For the talkers: “The superior man acts before he speaks, and afterwards speaks according to his action.” For everyone else: “Life is really simple, but we insist on making it complicated.”
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