arm/arm64: KVM: Fix set_clear_sgi_pend_reg offset

The sgi values calculated in read_set_clear_sgi_pend_reg() and
write_set_clear_sgi_pend_reg() were horribly incorrectly multiplied by 4
with catastrophic results in that subfunctions ended up overwriting
memory not allocated for the expected purpose.

This showed up as bugs in kfree() and the kernel complaining a lot of
you turn on memory debugging.

This addresses: http://marc.info/?l=kvm&m=141164910007868&w=2

Reported-by: Shannon Zhao <zhaoshenglong@huawei.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index b6fab0f25f3b64a4a44c0f06a566fc6d90d5541d..862967852d5afc7566f2ae20c027bb52183f25bc 100644 (file)
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -816,7 +816,7 @@ static bool read_set_clear_sgi_pend_reg(struct kvm_vcpu *vcpu,
 {
        struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
        int sgi;
-       int min_sgi = (offset & ~0x3) * 4;
+       int min_sgi = (offset & ~0x3);
        int max_sgi = min_sgi + 3;
        int vcpu_id = vcpu->vcpu_id;
        u32 reg = 0;
@@ -837,7 +837,7 @@ static bool write_set_clear_sgi_pend_reg(struct kvm_vcpu *vcpu,
 {
        struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
        int sgi;
-       int min_sgi = (offset & ~0x3) * 4;
+       int min_sgi = (offset & ~0x3);
        int max_sgi = min_sgi + 3;
        int vcpu_id = vcpu->vcpu_id;
        u32 reg;