From: Marios Pomonis pomonis@google.com
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@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
--- arch/x86/kvm/ioapic.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/arch/x86/kvm/ioapic.c +++ b/arch/x86/kvm/ioapic.c @@ -36,6 +36,7 @@ #include <linux/io.h> #include <linux/slab.h> #include <linux/export.h> +#include <linux/nospec.h> #include <asm/processor.h> #include <asm/page.h> #include <asm/current.h> @@ -299,6 +300,7 @@ 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 */