From 56b51e25ffb93ae142652400c35ea43f0899d0c2 Mon Sep 17 00:00:00 2001 From: Marios Pomonis Date: Wed, 11 Dec 2019 12:47:45 -0800 Subject: [PATCH] KVM: x86: Protect ioapic_write_indirect() from Spectre-v1/L1TF attacks commit 670564559ca35b439c8d8861fc399451ddf95137 upstream. This fixes a Spectre-v1/L1TF vulnerability in ioapic_write_indirect(). This function contains index computations based on the (attacker-controlled) IOREGSEL register. This patch depends on patch "KVM: x86: Protect ioapic_read_indirect() from Spectre-v1/L1TF attacks". Fixes: 70f93dae32ac ("KVM: Use temporary variable to shorten lines.") Signed-off-by: Nick Finco Signed-off-by: Marios Pomonis Reviewed-by: Andrew Honig Reviewed-by: Jim Mattson Signed-off-by: Paolo Bonzini [bwh: Backported to 3.16: adjust filename] Signed-off-by: Ben Hutchings --- virt/kvm/ioapic.c | 1 + 1 file changed, 1 insertion(+) diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c index c022e959dd887..456131c04c903 100644 --- a/virt/kvm/ioapic.c +++ b/virt/kvm/ioapic.c @@ -312,6 +312,7 @@ static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val) ioapic_debug("change redir index %x val %x\n", index, val); if (index >= IOAPIC_NUM_PINS) return; + index = array_index_nospec(index, IOAPIC_NUM_PINS); e = &ioapic->redirtbl[index]; mask_before = e->fields.mask; if (ioapic->ioregsel & 1) { -- 2.47.2