The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 64afe6e9eb4841f35317da4393de21a047a883b3 Mon Sep 17 00:00:00 2001

From: Marc Zyngier marc.zyngier@arm.com Date: Thu, 16 Nov 2017 17:58:17 +0000 Subject: [PATCH] KVM: arm/arm64: vgic-its: Preserve the revious read from the pending table

The current pending table parsing code assumes that we keep the previous read of the pending bits, but keep that variable in the current block, making sure it is discarded on each loop.

We end-up using whatever is on the stack. Who knows, it might just be the right thing...

Fixes: 33d3bc9556a7d ("KVM: arm64: vgic-its: Read initial LPI pending table") Cc: stable@vger.kernel.org # 4.8 Reported-by: AKASHI Takahiro takahiro.akashi@linaro.org Reviewed-by: Christoffer Dall christoffer.dall@linaro.org Signed-off-by: Marc Zyngier marc.zyngier@arm.com Signed-off-by: Christoffer Dall christoffer.dall@linaro.org

diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c index 1f761a9991e7..cb2d0a2dbe5a 100644 --- a/virt/kvm/arm/vgic/vgic-its.c +++ b/virt/kvm/arm/vgic/vgic-its.c @@ -421,6 +421,7 @@ static int its_sync_lpi_pending_table(struct kvm_vcpu *vcpu) u32 *intids; int nr_irqs, i; unsigned long flags; + u8 pendmask;

nr_irqs = vgic_copy_lpi_list(vcpu, &intids); if (nr_irqs < 0) @@ -428,7 +429,6 @@ static int its_sync_lpi_pending_table(struct kvm_vcpu *vcpu)

for (i = 0; i < nr_irqs; i++) { int byte_offset, bit_nr; - u8 pendmask;

byte_offset = intids[i] / BITS_PER_BYTE; bit_nr = intids[i] % BITS_PER_BYTE;