KVM: x86: Protect ioapic_write_indirect() from Spectre-v1/L1TF attacks

commit 670564559c 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: 70f93dae32 ("KVM: Use temporary variable to shorten lines.")

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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Marios Pomonis 2019-12-11 12:47:45 -08:00 committed by Greg Kroah-Hartman
parent c8a6b59189
commit 2f8a13754e
1 changed files with 1 additions and 0 deletions

View File

@ -291,6 +291,7 @@ static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 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 */