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

diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index c55f72eb54663ea1f318077d572ff1dbe3839219..5ac934b48d4ac353018cbad8666f77f6e6e61aea 100644 (file)
--- 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 */