Date: Sat, 23 Sep 2017 13:29:32 +0200 From: Ingo Molnar <mingo@...nel.org> To: Eric Biggers <ebiggers3@...il.com> Cc: x86@...nel.org, linux-kernel@...r.kernel.org, kernel-hardening@...ts.openwall.com, Andy Lutomirski <luto@...nel.org>, Dave Hansen <dave.hansen@...ux.intel.com>, Dmitry Vyukov <dvyukov@...gle.com>, Fenghua Yu <fenghua.yu@...el.com>, Kevin Hao <haokexin@...il.com>, Oleg Nesterov <oleg@...hat.com>, Wanpeng Li <wanpeng.li@...mail.com>, Yu-cheng Yu <yu-cheng.yu@...el.com>, Michael Halcrow <mhalcrow@...gle.com>, Eric Biggers <ebiggers@...gle.com> Subject: Re: [PATCH] x86/fpu: Simplify fpu__activate_fpstate_read() * Ingo Molnar <mingo@...nel.org> wrote: > > * Eric Biggers <ebiggers3@...il.com> wrote: > > > On Fri, Sep 22, 2017 at 07:33:14AM +0200, Ingo Molnar wrote: > > > > > > * Eric Biggers <ebiggers3@...il.com> wrote: > > > > > > > From: Eric Biggers <ebiggers@...gle.com> > > > > > > > > This series fixes the bug found by syzkaller where the ptrace syscall > > > > can be used to set invalid bits in a task's FPU state. I also found > > > > that an equivalent bug was reachable using the sigreturn syscall, so the > > > > first patch fixes the bug in both cases. > > > > > > > > The other two patches start validating the other parts of the > > > > xstate_header and make it so that invalid FPU states can no longer be > > > > abused to leak the FPU registers of other processes. > > > > > > > > Changes since v2: > > > > - Use an exception handler to handle invalid FPU states > > > > (suggested by Andy Lutomirski) > > > > - Check the size of xstate_header.reserved at build time > > > > (suggested by Dave Hansen) > > > > > > > > Eric Biggers (3): > > > > x86/fpu: don't let userspace set bogus xcomp_bv > > > > x86/fpu: tighten validation of user-supplied xstate_header > > > > x86/fpu: reinitialize FPU registers if restoring FPU state fails > > > > > > > > arch/x86/include/asm/fpu/internal.h | 51 +++++++++++-------------------------- > > > > arch/x86/include/asm/fpu/xstate.h | 25 ++++++++++++++++++ > > > > arch/x86/kernel/fpu/regset.c | 20 +++++++-------- > > > > arch/x86/kernel/fpu/signal.c | 15 ++++++++--- > > > > arch/x86/kernel/fpu/xstate.c | 27 ++++++++------------ > > > > arch/x86/mm/extable.c | 24 +++++++++++++++++ > > > > 6 files changed, 94 insertions(+), 68 deletions(-) > > > > > > Ok - could you please rebase these to to tip:master that is at: > > > > > > git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git master > > > > > > In particular this has a WIP.x86/fpu branch with FPU fixes+changes queued up but > > > not merged upstream (yet), which conflict with these changes. I'd like to merge > > > them all together. > > > > > > > Working on it, but there is a problem with current tip. PTRACE_GETREGSET is > > causing the following warning: > > Yes, the warning should be harmless, and I fixed it locally earlier today - does > the patch below solve it for you as well? Note that this fix is now part of tip:master as well, so if you re-test -tip you should get all the latest fixes as well (including yours!). Thanks, Ingo
Powered by blists - more mailing lists
Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.