From: Andy Lutomirski <luto@kernel.org>
To: Peter Zijlstra <peterz@infradead.org>,
Steven Rostedt <rostedt@goodmis.org>
Cc: "security@kernel.org" <security@kernel.org>,
Andy Lutomirski <luto@kernel.org>,
Andrew Cooper <andrew.cooper3@citrix.com>,
X86 ML <x86@kernel.org>,
linux-kernel@vger.kernel.org, xen-devel <xen-devel@lists.xen.org>,
Borislav Petkov <bp@alien8.de>, Jan Beulich <jbeulich@suse.com>,
Sasha Levin <sasha.levin@oracle.com>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>
Subject: [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option
Date: Fri, 24 Jul 2015 22:36:43 -0700 [thread overview]
Message-ID: <cover.1437802102.git.luto__47317.4748513431$1437802725$gmane$org@kernel.org> (raw)
Here's v3. It fixes the "dazed and confused" issue, I hope. It's also
probably a good general attack surface reduction, and it replaces some
scary code with IMO less scary code.
Also, servers and embedded systems should probably turn off modify_ldt.
This makes that possible.
Xen people, can you take a look at this?
Willy and Kees: I left the config option alone. The -tiny people will
like it, and we can always add a sysctl of some sort later.
Changes from v3:
- Hopefully fixed Xen.
- Fixed 32-bit test case on 32-bit native kernel.
- Fix bogus vumnap for some LDT sizes.
- Strengthen test case to check all LDT sizes (catches bogus vunmap).
- Lots of cleanups, mostly from Borislav.
- Simplify IPI code using on_each_cpu_mask.
Changes from v2:
- Allocate ldt_struct and the LDT entries separately. This should fix Xen.
- Stop using write_ldt_entry, since I'm pretty sure it's unnecessary now
that we no longer mutate an in-use LDT. (Xen people, can you check?)
Changes from v1:
- The config option is new.
- The test case is new.
- Fixed a missing allocation failure check.
- Fixed a use-after-free on fork().
Andy Lutomirski (3):
x86/ldt: Make modify_ldt synchronous
x86/ldt: Make modify_ldt optional
selftests/x86, x86/ldt: Add a selftest for modify_ldt
arch/x86/Kconfig | 17 ++
arch/x86/include/asm/desc.h | 15 --
arch/x86/include/asm/mmu.h | 5 +-
arch/x86/include/asm/mmu_context.h | 68 ++++-
arch/x86/kernel/Makefile | 3 +-
arch/x86/kernel/cpu/common.c | 4 +-
arch/x86/kernel/cpu/perf_event.c | 16 +-
arch/x86/kernel/ldt.c | 262 +++++++++---------
arch/x86/kernel/process_64.c | 6 +-
arch/x86/kernel/step.c | 8 +-
arch/x86/power/cpu.c | 3 +-
kernel/sys_ni.c | 1 +
tools/testing/selftests/x86/Makefile | 2 +-
tools/testing/selftests/x86/ldt_gdt.c | 492 ++++++++++++++++++++++++++++++++++
14 files changed, 747 insertions(+), 155 deletions(-)
create mode 100644 tools/testing/selftests/x86/ldt_gdt.c
--
2.4.3
next reply other threads:[~2015-07-25 5:36 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-25 5:36 Andy Lutomirski [this message]
[not found] <cover.1437802102.git.luto@kernel.org>
2015-07-25 6:27 ` [PATCH v4 0/3] x86: modify_ldt improvement, test, and config option Willy Tarreau
2015-07-27 15:36 ` Boris Ostrovsky
[not found] ` <55B64FEA.70204@oracle.com>
2015-07-27 15:53 ` Andy Lutomirski
[not found] ` <CALCETrUEYTCwYzA0bvG=EJOi+pdXX=FZXoaQc4tYGkJATM7x3g@mail.gmail.com>
2015-07-27 16:18 ` Boris Ostrovsky
[not found] ` <55B659EC.5030009@oracle.com>
2015-07-28 2:20 ` Andy Lutomirski
[not found] ` <CALCETrV7zVbt0ZV4KYcSTUHjAOxzGmu3SXWoT7iECB=zWSN7Ew@mail.gmail.com>
2015-07-28 3:16 ` Andy Lutomirski
[not found] ` <CALCETrV275oYQY80yg6TJ-h9n2Db-uF-po90bF+JmKjnV5ZqYw@mail.gmail.com>
2015-07-28 3:23 ` Andy Lutomirski
2015-07-28 3:43 ` Boris Ostrovsky
2015-07-28 10:29 ` Andrew Cooper
[not found] ` <55B75993.90909@citrix.com>
2015-07-28 14:05 ` Boris Ostrovsky
[not found] ` <55B78C35.1050702@oracle.com>
2015-07-28 14:35 ` Andrew Cooper
[not found] ` <55B79314.8060009@citrix.com>
2015-07-28 14:50 ` Boris Ostrovsky
[not found] ` <55B796BF.1080005@oracle.com>
2015-07-28 15:15 ` Konrad Rzeszutek Wilk
2015-07-28 15:23 ` Andrew Cooper
[not found] ` <20150728151527.GI26623@x230.dumpdata.com>
2015-07-28 15:39 ` Boris Ostrovsky
[not found] ` <55B79E75.4010000@citrix.com>
2015-07-28 15:59 ` Boris Ostrovsky
2015-07-28 15:43 ` Andy Lutomirski
[not found] ` <CALCETrXt2OP=+JAj7gzUOJT+5=00Qg3Te11twSeK8F_9zn_nwg@mail.gmail.com>
2015-07-28 16:30 ` Andrew Cooper
[not found] ` <55B7AE39.7000101@citrix.com>
2015-07-28 17:07 ` Andy Lutomirski
[not found] ` <CALCETrVd56uwkZw0YtaSHKHp5dh7NugQouigibJkr=e3Q_mYyA@mail.gmail.com>
2015-07-28 17:10 ` Boris Ostrovsky
[not found] ` <55B7B791.2050208@oracle.com>
2015-07-29 0:21 ` Andy Lutomirski
[not found] ` <CALCETrXH5_PMqfH1en_5c+5gUpq8SjCnQ3Xaz-K6ej6FgBgLDQ@mail.gmail.com>
2015-07-29 0:47 ` Andrew Cooper
[not found] ` <55B822B8.3090608@citrix.com>
2015-07-29 3:01 ` Boris Ostrovsky
[not found] ` <55B841FF.2000102@oracle.com>
2015-07-29 4:26 ` Andy Lutomirski
2015-07-29 5:28 ` Andy Lutomirski
[not found] ` <CALCETrWkMRb+Y3FsJ7+kNYmPxtupM3ZPOeOPwagXytgBqM6tJQ@mail.gmail.com>
2015-07-29 14:21 ` Andrew Cooper
[not found] ` <55B8E16C.2050406@citrix.com>
2015-07-29 14:43 ` Boris Ostrovsky
[not found] ` <55B8E68B.2030305@oracle.com>
2015-07-29 19:03 ` Andrew Cooper
[not found] ` <55B9236B.9090507@citrix.com>
2015-07-29 21:23 ` Boris Ostrovsky
[not found] ` <55B94451.8040600@oracle.com>
2015-07-29 21:26 ` Andy Lutomirski
[not found] ` <CALCETrWA=hAyqqp=yzZ2r_S=9U9hLkd6dZEuNefew8hyLVA_eQ@mail.gmail.com>
2015-07-29 21:33 ` Boris Ostrovsky
2015-07-29 21:37 ` Andrew Cooper
[not found] ` <55B947AF.7020404@citrix.com>
2015-07-29 22:05 ` Andy Lutomirski
[not found] ` <CALCETrXp_DV-_Uvekwv7xLHO-5P8Oxkgn6OeXG-6tVOD4RkKMw@mail.gmail.com>
2015-07-29 22:11 ` Andrew Cooper
[not found] ` <55B94F9D.3000405@citrix.com>
2015-07-29 22:40 ` Boris Ostrovsky
2015-07-29 22:46 ` David Vrabel
2015-07-29 22:49 ` Boris Ostrovsky
[not found] ` <55B95863.2000102@oracle.com>
2015-07-29 22:55 ` David Vrabel
2015-07-29 23:02 ` Andrew Cooper
[not found] ` <55B95B70.8010902@citrix.com>
2015-07-29 23:13 ` Andy Lutomirski
[not found] ` <CALCETrWy93qobHmMWzTfqFN+0Y7DGyM7viwpPMGOeSiXEP0Z6w@mail.gmail.com>
2015-07-30 0:29 ` Andrew Cooper
[not found] ` <55B96FE0.6010600@citrix.com>
2015-07-30 18:30 ` Andy Lutomirski
[not found] ` <CALCETrUi2GBdGP2OX+3PwSf0UYjKuf2+DugENe3Y6mUoy-Rfkw@mail.gmail.com>
2015-07-30 18:54 ` Andrew Cooper
[not found] ` <55BA72E1.4050809@citrix.com>
2015-07-30 20:01 ` Boris Ostrovsky
[not found] ` <55BA828E.8070304@oracle.com>
2015-07-30 20:05 ` Andy Lutomirski
[not found] ` <CALCETrUsFn23tKf418VSbGCgXoXXRq8dk41ZfM3F55=_xWPQhw@mail.gmail.com>
2015-07-30 20:18 ` Boris Ostrovsky
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