Messages in this thread Patch in this message | | | From | Ingo Molnar <> | Subject | [PATCH 02/10] x86/fpu: Use validate_xstate_header() to validate the xstate_header in xstateregs_set() | Date | Sun, 24 Sep 2017 12:59:05 +0200 |
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From: Eric Biggers <ebiggers@google.com>
Tighten the checks in xstateregs_set().
Signed-off-by: Eric Biggers <ebiggers@google.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kevin Hao <haokexin@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Halcrow <mhalcrow@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Cc: kernel-hardening@lists.openwall.com Signed-off-by: Ingo Molnar <mingo@kernel.org> --- arch/x86/kernel/fpu/regset.c | 19 ++++++------------- 1 file changed, 6 insertions(+), 13 deletions(-)
diff --git a/arch/x86/kernel/fpu/regset.c b/arch/x86/kernel/fpu/regset.c index ee8d2f049818..b831d5b9de99 100644 --- a/arch/x86/kernel/fpu/regset.c +++ b/arch/x86/kernel/fpu/regset.c @@ -141,27 +141,20 @@ int xstateregs_set(struct task_struct *target, const struct user_regset *regset, ret = copy_user_to_xstate(xsave, ubuf); } else { ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, xsave, 0, -1); - - /* xcomp_bv must be 0 when using uncompacted format */ - if (!ret && xsave->header.xcomp_bv) - ret = -EINVAL; + if (!ret) + ret = validate_xstate_header(&xsave->header); } /* - * In case of failure, mark all states as init: - */ - if (ret) - fpstate_init(&fpu->state); - - /* * mxcsr reserved bits must be masked to zero for security reasons. */ xsave->i387.mxcsr &= mxcsr_feature_mask; - xsave->header.xfeatures &= xfeatures_mask; + /* - * These bits must be zero. + * In case of failure, mark all states as init: */ - memset(&xsave->header.reserved, 0, 48); + if (ret) + fpstate_init(&fpu->state); return ret; } -- 2.11.0
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