Messages in this thread | | | From | Kees Cook <> | Date | Tue, 19 Sep 2017 20:03:05 -0700 | Subject | Re: [PATCH v2 0/3] x86/fpu: prevent leaking FPU registers via invalid FPU state |
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On Tue, Sep 19, 2017 at 5:44 PM, Eric Biggers <ebiggers3@gmail.com> wrote: > From: Eric Biggers <ebiggers@google.com> > > This is a second attempt to fix 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. > > 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
This series looks sensible to me! Thanks for getting this fixed up.
Reviewed-by: Kees Cook <keescook@chromium.org>
-Kees
> > arch/x86/include/asm/fpu/internal.h | 29 ++++++++++++++++++++--------- > arch/x86/include/asm/fpu/xstate.h | 19 +++++++++++++++++++ > arch/x86/kernel/fpu/core.c | 16 ++++++++++++++++ > arch/x86/kernel/fpu/regset.c | 20 +++++++++----------- > arch/x86/kernel/fpu/signal.c | 15 +++++++++++---- > arch/x86/kernel/fpu/xstate.c | 27 ++++++++++----------------- > 6 files changed, 85 insertions(+), 41 deletions(-) > > -- > 2.14.1.690.gbb1197296e-goog >
-- Kees Cook Pixel Security
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