The patch below does not apply to the 5.16-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 063452fd94d153d4eb38ad58f210f3d37a09cca4 Mon Sep 17 00:00:00 2001 From: Yang Zhong yang.zhong@intel.com Date: Sat, 29 Jan 2022 09:36:46 -0800 Subject: [PATCH] x86/fpu/xstate: Fix the ARCH_REQ_XCOMP_PERM implementation

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@intel.com Signed-off-by: Chang S. Bae chang.seok.bae@intel.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Cc: Paolo Bonzini bonzini@gnu.org Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20220129173647.27981-2-chang.seok.bae@intel.com

diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 7c7824ae7862..dc6d5e98d296 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -1639,7 +1639,7 @@ static int __xstate_request_perm(u64 permitted, u64 requested, bool guest)

perm = guest ? &fpu->guest_perm : &fpu->perm; /* Pairs with the READ_ONCE() in xstate_get_group_perm() */ - WRITE_ONCE(perm->__state_perm, requested); + WRITE_ONCE(perm->__state_perm, mask); /* Protected by sighand lock */ perm->__state_size = ksize; perm->__user_state_size = usize;