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linux/virt/kvm/arm
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Gustavo A. R. Silva 70bf6988a3 KVM: arm/arm64: vgic: Fix off-by-one bug in vgic_get_irq() 
commit c23b2e6fc4 upstream.

When using the nospec API, it should be taken into account that:

"...if the CPU speculates past the bounds check then
 * array_index_nospec() will clamp the index within the range of [0,
 * size)."

The above is part of the header for macro array_index_nospec() in
linux/nospec.h

Now, in this particular case, if intid evaluates to exactly VGIC_MAX_SPI
or to exaclty VGIC_MAX_PRIVATE, the array_index_nospec() macro ends up
returning VGIC_MAX_SPI - 1 or VGIC_MAX_PRIVATE - 1 respectively, instead
of VGIC_MAX_SPI or VGIC_MAX_PRIVATE, which, based on the original logic:

	/* SGIs and PPIs */
	if (intid <= VGIC_MAX_PRIVATE)
 		return &vcpu->arch.vgic_cpu.private_irqs[intid];

 	/* SPIs */
	if (intid <= VGIC_MAX_SPI)
 		return &kvm->arch.vgic.spis[intid - VGIC_NR_PRIVATE_IRQS];

are valid values for intid.

Fix this by calling array_index_nospec() macro with VGIC_MAX_PRIVATE + 1
and VGIC_MAX_SPI + 1 as arguments for its parameter size.

Fixes: 41b87599c7 ("KVM: arm/arm64: vgic: fix possible spectre-v1 in vgic_get_irq()")
Cc: stable@vger.kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
[dropped the SPI part which was fixed separately]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2019-01-09 17:46:04 +01:00
..
hyp kvm/arm fixes for 4.16, take 2 2018-03-19 17:43:01 +00:00
vgic KVM: arm/arm64: vgic: Fix off-by-one bug in vgic_get_irq() 2019-01-09 17:46:04 +01:00
aarch32.c kvm/arm: use PSR_AA32 definitions 2018-07-05 17:24:15 +01:00
arch_timer.c KVM: arm/arm64: Fix lost IRQs from emulated physcial timer when blocked 2018-07-31 07:53:20 +01:00
arm.c KVM: arm/arm64: Fix VMID alloc race by reverting to lock-less 2019-01-09 17:46:04 +01:00
mmio.c KVM: Fix stack-out-of-bounds read in write_mmio 2017-12-18 12:57:01 +01:00
mmu.c KVM updates for v4.20 2018-10-25 17:57:35 -07:00
perf.c KVM: arm/arm64: Move shared files to virt/kvm/arm 2017-05-04 13:57:26 +02:00
pmu.c KVM: arm64: Rewrite system register accessors to read/write functions 2018-03-19 10:53:16 +00:00
psci.c sched/swait: Rename to exclusive 2018-06-20 11:35:56 +02:00
trace.h KVM: Remove obsolete kvm_unmap_hva notifier backend 2018-09-07 15:06:02 +02:00