Date: Wed, 2 Apr 2014 11:22:32 -0400 From: Shawn Webb <lattera@gmail.com> To: Oliver Pinter <oliver.pntr@gmail.com> Cc: FreeBSD-current <freebsd-current@freebsd.org> Subject: Re: [CFT] ASLR and PIE on amd64 Message-ID: <20140402152232.GF20907@pwnie.vrt.sourcefire.com> In-Reply-To: <CAPjTQNEJh6xqOLC0gCZV2zjtqaJtw9%2Brxfg5jW6XJiVSVxWaEA@mail.gmail.com> References: <CADt0fhzxTF=CoRZSLXv3MpKJisZx1kCd48O3wqkSL-8vL3ogaA@mail.gmail.com> <CAPjTQNFe7mrBCWNqWiJPPW7kkE9RyhEH-3XqvVkqDzb%2B-YrZkg@mail.gmail.com> <20140331002436.GB14025@pwnie.vrt.sourcefire.com> <CAPjTQNH1x7UYVrV60QpaE3-q%2BJ%2B5OXRnNxhN=_UYpua-VJWvUA@mail.gmail.com> <CAPjTQNEJh6xqOLC0gCZV2zjtqaJtw9%2Brxfg5jW6XJiVSVxWaEA@mail.gmail.com>
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--nYySOmuH/HDX6pKp Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Apr 02, 2014 04:54 PM +0200, Oliver Pinter wrote: > On 4/2/14, Oliver Pinter <oliver.pntr@gmail.com> wrote: > > On 3/31/14, Shawn Webb <lattera@gmail.com> wrote: > >> On Mar 31, 2014 02:07 AM +0200, Oliver Pinter wrote: > >>> On 3/22/14, Shawn Webb <lattera@gmail.com> wrote: > >>> > Hey All, > >>> > > >>> > First off, I hope that even as a non-committer, it's okay that I po= st > >>> > a call for testing. If not, please excuse my newbishness in this > >>> > process. This is my first time submitting a major patch upstream to > >>> > FreeBSD. > >>> > > >>> > Over the past few months, I've had the opportunity and pleasure to > >>> > enhance existing patches to FreeBSD that implement a common exploit > >>> > mitigation technology called Address Space Layout Randomization (AS= LR) > >>> > along with support for Position Independent Executables (PIE). > >>> > ASLR+PIE has been a long-requested feature by many people I've met = on > >>> > IRC. > >>> > > >>> > I've submitted my patch to PR kernel/181497. I'm currently in the > >>> > process of adding PIE support to certain high-visibility applicatio= ns > >>> > in base (mainly network daemons). I've added a make.conf knob that's > >>> > default to enabled (WITH_PIE=3D1). An application has to also expli= citly > >>> > support PIE as well by defining CAN_PIE in the Makefile prior to > >>> > including bsd.prog.mk. After I get a decent amount of applications > >>> > enabled with PIE support, I'll submit one last patch. > >>> > > >>> > The following sysctl's can be set with a kernel compiled with the > >>> > PAX_ASLR option: > >>> > > >>> > security.pax.aslr.status: 1 > >>> > security.pax.aslr.debug: 0 > >>> > security.pax.aslr.mmap_len: 16 > >>> > security.pax.aslr.stack_len: 12 > >>> > security.pax.aslr.exec_len: 12 > >>> > > >>> > The security.pax.aslr.status sysctl enables and disables the ASLR > >>> > system as a whole. The debug sysctl gives debugging output. The > >>> > mmap_len sysctl tells the ASLR system how many bits to randomize wi= th > >>> > mmap() is called. The stack_len sysctl tells the ASLR system how ma= ny > >>> > bits to randomize in the stack. The exec_len sysctl tells the ASLR > >>> > system how many bits to randomize the execbase (this controls PIE). > >>> > These sysctls can be set as a per-jail basis. If you have an > >>> > application which doesn't support ASLR, yet you want ASLR enabled f= or > >>> > everything else, you can simply place that misbehaving application = in > >>> > a jail with only that jail's ASLR settings turned off. > >>> > > >>> > Please let me know how your testing goes. I'm giving a presentation= at > >>> > BSDCan regarding this. > >>> > > >>> > If you want to keep tabs on my bleeding-edge development process, > >>> > please follow my progress on GitHub: > >>> > https://github.com/lattera/freebsd (branch: soldierx/lattera/aslr). > >>> > > >>> > Thank you very much, > >>> > >>> Hi! > >>> > >>> Please apply this patch. This fixed an issue with tunables. > >> > >> Patch merged successfully into my GitHub repo. Fixed with commit > >> d2c0813. I'll include it in my next patch submission upstream when I > >> submit my PIE work. Thanks! > > > > please see the attached patch, compile and boot tested on amd64 >=20 >=20 > Some more patches, and one critical fix > (0006-PAX-ASLR-use-the-right-sysent-before-this-commit-cal.patch). You are awesome. I'll integrate those patches today. In reviewing your patches, I noticed a few places where I'm keying off the local pax_aslr_debug variable. I ought to switch that to keying off the jail's pr_pax_aslr_debug variable. --nYySOmuH/HDX6pKp Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (FreeBSD) iQIcBAEBAgAGBQJTPCs4AAoJEGqEZY9SRW7uuywP/Rfmo7sBoJil2wVXCKKVCB5r NhvnQ3FKItUqj3S1iz/VJFEPo69CyfQedaQSut1i59faznEWF4kul7yUlHFcacjq bulg3ES91ZnbBSQuU8gNwNX4MQYAgamfRltIlGppNhLJqOTfuu2SfTEIbWS4lAKa +AjxPKs2IFbMmHTUDj/8siMISk3mGhePM2S8iZOiGsY6emBjMkOGMPghjI2B+Vsf oW6wtV2zhFcVlPLJFhaCX5dKL0pG3OxLLpFglsvmj0qcvQ19VnTylC/9GuP8D7ts /bxXtU25KZCVLetpS4SJd13axFUdQaauWMMM0WqaiNFA2a0SLO7xoyMC5/wb0V53 PaB+LqwTIIQ+HoxVfs55+d6kG/vvBMGird9E5ldRSD/MioDx4Ngnv6dWLZIFgdui NxBaPmtiFZuXZIkN4UmwYm8eIQW4fptS4jKylHH4pC0obYZU4SN/Uqr6BbNZKGKp 6lDjFD5FtF8XQigrmlrFbu+vjQqbG9gaNiO4pSO5mtZ9s2rjD+/UZfpv8dVxrsne NkezaRxwLvh1Kdc7sCSyKFEFVEMbe69Wf2Y9NGq0rJlddGVhwf2Iwp+QJHSzSAaq +HXfdJTj1ZKbqwqvuevW9nTUjZ5WdGHGE6LqnVM2Qj+JUaXRiVhjzvJj38KVBZHT 59O63scsVvsRqwRM2rOa =heSp -----END PGP SIGNATURE----- --nYySOmuH/HDX6pKp--
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