From: Marios Pomonis <pomonis@xxxxxxxxxx>
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 <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/ioapic.c | 1 +
1 file changed, 1 insertion(+)
--- a/arch/x86/kvm/ioapic.c
+++ b/arch/x86/kvm/ioapic.c
@@ -297,6 +297,7 @@ static void ioapic_write_indirect(struct
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;
/* Preserve read-only fields */
