Messages in this thread Patch in this message | | | From | "Fenghua Yu" <> | Subject | [PATCH 1/4] x86/fpu/xstate: Fix __fpu_restore_sig() for XSAVES | Date | Mon, 11 Jul 2016 09:18:54 -0700 |
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From: Yu-cheng Yu <yu-cheng.yu@intel.com>
When the kernel is using XSAVES compacted format, we cannot do __copy_from_user() from a signal frame, which has standard-format data. Fix it by using copyin_to_xsaves(), which converts between formats and filters out all supervisor states that we do not allow userspace to write.
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Reviewed-by: Dave Hansen <dave.hansen@intel.com> --- arch/x86/kernel/fpu/signal.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c index 8aa96cb..9e231d8 100644 --- a/arch/x86/kernel/fpu/signal.c +++ b/arch/x86/kernel/fpu/signal.c @@ -323,8 +323,15 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size) */ fpu__drop(fpu); - if (__copy_from_user(&fpu->state.xsave, buf_fx, state_size) || - __copy_from_user(&env, buf, sizeof(env))) { + if (using_compacted_format()) { + err = copyin_to_xsaves(NULL, buf_fx, + &fpu->state.xsave); + } else { + err = __copy_from_user(&fpu->state.xsave, + buf_fx, state_size); + } + + if (err || __copy_from_user(&env, buf, sizeof(env))) { fpstate_init(&fpu->state); trace_x86_fpu_init_state(fpu); err = -1; -- 2.5.0
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