[PATCH 49/55] KVM: arm64: vgic-its: Validate the device table L1 entry
From: Marc Zyngier <hidden>
Date: 2016-07-22 17:29:06
Also in:
kvm, kvmarm
Subsystem:
kernel virtual machine (kvm), the rest · Maintainers:
Paolo Bonzini, Linus Torvalds
Checking that the device_id fits if the table, and we must make sure that the associated memory is also accessible. Signed-off-by: Marc Zyngier <redacted> --- virt/kvm/arm/vgic/vgic-its.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index 268a0c7..4943d6a 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c@@ -693,8 +693,17 @@ static bool vgic_its_check_device_id(struct kvm *kvm, struct vgic_its *its, gfn_t gfn; - if (!(r & GITS_BASER_INDIRECT)) - return device_id < (l1_tbl_size / GITS_BASER_ENTRY_SIZE(r)); + if (!(r & GITS_BASER_INDIRECT)) { + phys_addr_t addr; + + if (device_id >= (l1_tbl_size / GITS_BASER_ENTRY_SIZE(r))) + return false; + + addr = BASER_ADDRESS(r) + device_id * GITS_BASER_ENTRY_SIZE(r); + gfn = addr >> PAGE_SHIFT; + + return kvm_is_visible_gfn(kvm, gfn); + } /* calculate and check the index into the 1st level */ index = device_id / (SZ_64K / GITS_BASER_ENTRY_SIZE(r));
--
2.8.1