From: Marios Pomonis <pomonis@xxxxxxxxxx>
commit 14e32321f3606e4b0970200b6e5e47ee6f1e6410 upstream.
This fixes a Spectre-v1/L1TF vulnerability in picdev_write().
It replaces index computations based on the (attacked-controlled) port
number with constants through a minor refactoring.
Fixes: 85f455f7ddbe ("KVM: Add support for in-kernel PIC emulation")
Signed-off-by: Nick Finco <nifi@xxxxxxxxxx>
Signed-off-by: Marios Pomonis <pomonis@xxxxxxxxxx>
Reviewed-by: Andrew Honig <ahonig@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Jim Mattson <jmattson@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kvm/i8259.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
--- a/arch/x86/kvm/i8259.c
+++ b/arch/x86/kvm/i8259.c
@@ -460,10 +460,14 @@ static int picdev_write(struct kvm_pic *
switch (addr) {
case 0x20:
case 0x21:
+ pic_lock(s);
+ pic_ioport_write(&s->pics[0], addr, data);
+ pic_unlock(s);
+ break;
case 0xa0:
case 0xa1:
pic_lock(s);
- pic_ioport_write(&s->pics[addr >> 7], addr, data);
+ pic_ioport_write(&s->pics[1], addr, data);
pic_unlock(s);
break;
case 0x4d0:
