Re: [PATCH][Rebased for 5.16] x86/fpu/xstate: Fix the ARCH_REQ_XCOMP_PERM implementation

From: Greg KH
Date: Mon Apr 11 2022 - 09:28:57 EST


On Tue, Apr 05, 2022 at 04:04:56AM -0700, Chang S. Bae wrote:
> From: Yang Zhong <yang.zhong@xxxxxxxxx>
>
> This is backport for 5.16
>
> Upstream commit 063452fd94d153d4eb38ad58f210f3d37a09cca4
>
> ARCH_REQ_XCOMP_PERM is supposed to add the requested feature to the
> permission bitmap of thread_group_leader()->fpu. But the code overwrites
> the bitmap with the requested feature bit only rather than adding it.
>
> Fix the code to add the requested feature bit to the master bitmask.
>
> Fixes: db8268df0983 ("x86/arch_prctl: Add controls for dynamic XSTATE components")
> Signed-off-by: Yang Zhong <yang.zhong@xxxxxxxxx>
> Signed-off-by: Chang S. Bae <chang.seok.bae@xxxxxxxxx>
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Paolo Bonzini <bonzini@xxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> Link: https://lore.kernel.org/r/20220129173647.27981-2-chang.seok.bae@xxxxxxxxx
> [chang: Backport for 5.16]
> Signed-off-by: Chang S. Bae <chang.seok.bae@xxxxxxxxx>
> ---
> arch/x86/kernel/fpu/xstate.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)

Now queued up, thanks.

greg k-h