4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mark Rutland <mark.rutland@xxxxxxx> [ Upstream commit 5e1ca5e23b167987d5b6d8b08f2d5b7dd2d13f49 ] It's possible for userspace to control n. Sanitize n when using it as an array index. Note that while it appears that n must be bound to the interval [0,3] due to the way it is extracted from addr, we cannot guarantee that compiler transformations (and/or future refactoring) will ensure this is the case, and given this is a slow path it's better to always perform the masking. Found by smatch. Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx> Acked-by: Christoffer Dall <christoffer.dall@xxxxxxx> Acked-by: Marc Zyngier <marc.zyngier@xxxxxxx> Cc: kvmarm@xxxxxxxxxxxxxxxxxxxxx Signed-off-by: Will Deacon <will.deacon@xxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- virt/kvm/arm/vgic/vgic-mmio-v2.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/virt/kvm/arm/vgic/vgic-mmio-v2.c +++ b/virt/kvm/arm/vgic/vgic-mmio-v2.c @@ -14,6 +14,8 @@ #include <linux/irqchip/arm-gic.h> #include <linux/kvm.h> #include <linux/kvm_host.h> +#include <linux/nospec.h> + #include <kvm/iodev.h> #include <kvm/arm_vgic.h> @@ -320,6 +322,9 @@ static unsigned long vgic_mmio_read_apr( if (n > vgic_v3_max_apr_idx(vcpu)) return 0; + + n = array_index_nospec(n, 4); + /* GICv3 only uses ICH_AP1Rn for memory mapped (GICv2) guests */ return vgicv3->vgic_ap1r[n]; }
