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| author | Marios Pomonis <pomonis@google.com> | 2019-12-11 12:47:43 -0800 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2020-05-22 21:19:37 +0100 |
| commit | 6356cde8b18ae7eb06a93d001e996168fce3efce (patch) | |
| tree | 6b5697a81c21c66241e37f9f6484e5e5a829ef95 | |
| parent | db929cc57463b056ff9aaaca6ed309464c029e01 (diff) | |
| download | linux-stable-6356cde8b18ae7eb06a93d001e996168fce3efce.tar.gz | |
KVM: x86: Refactor picdev_write() to prevent Spectre-v1/L1TF attacks
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@google.com>
Signed-off-by: Marios Pomonis <pomonis@google.com>
Reviewed-by: Andrew Honig <ahonig@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[bwh: Backported to 3.16: pic_{,un}lock() are called outside the switch]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | arch/x86/kvm/i8259.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c index cc31f7c06d3dd..08b2ad1df9f83 100644 --- a/arch/x86/kvm/i8259.c +++ b/arch/x86/kvm/i8259.c @@ -486,9 +486,11 @@ static int picdev_write(struct kvm_pic *s, switch (addr) { case 0x20: case 0x21: + pic_ioport_write(&s->pics[0], addr, data); + break; case 0xa0: case 0xa1: - pic_ioport_write(&s->pics[addr >> 7], addr, data); + pic_ioport_write(&s->pics[1], addr, data); break; case 0x4d0: case 0x4d1: |