From 781c64bfcb735960717d1cb45428047ff6a5030c Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Thu, 24 Mar 2022 14:47:14 +0100
Subject: [PATCH] x86/fpu/xstate: Handle supervisor states in XSTATE
permissions
The size calculation in __xstate_request_perm() fails to take supervisor
states into account because the permission bitmap is only relevant for user
states.
Up to 5.17 this does not matter because there are no supervisor states
supported, but the (re-)enabling of ENQCMD makes them available.
Fixes: 7c1ef59145f1 ("x86/cpufeatures: Re-enable ENQCMD")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220324134623.681768598@linutronix.de
---
arch/x86/kernel/fpu/xstate.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index c55f72eb54663..5ac934b48d4ac 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -1571,6 +1571,9 @@ static int __xstate_request_perm(u64 permitted, u64 requested, bool guest)
/* Calculate the resulting kernel state size */
mask = permitted | requested;
+ /* Take supervisor states into account on the host */
+ if (!guest)
+ mask |= xfeatures_mask_supervisor();
ksize = xstate_calculate_size(mask, compacted);
/* Calculate the resulting user state size */
--
2.30.2