diff options
| author | Marios Pomonis <pomonis@google.com> | 2019-12-11 12:47:43 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-02-14 16:30:00 -0500 |
| commit | 784258aaf66a4018dc277ecfa9f82e551e5abc49 (patch) | |
| tree | e1e9d0b6a9187e3631a9c553794263e19f3d6228 /arch/x86/kvm | |
| parent | 5372b007fa8a4930163c7aa997750f6288540ba6 (diff) | |
KVM: x86: Refactor picdev_write() to prevent Spectre-v1/L1TF attacks
[ Upstream commit 14e32321f3606e4b0970200b6e5e47ee6f1e6410 ]
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>
Cc: stable@vger.kernel.org
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch/x86/kvm')
| -rw-r--r-- | arch/x86/kvm/i8259.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c index ce0f29e5d7c4..791850bfc981 100644 --- a/arch/x86/kvm/i8259.c +++ b/arch/x86/kvm/i8259.c @@ -468,10 +468,14 @@ static int picdev_write(struct kvm_pic *s, 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: |