[PATCH 3.14 20/34] arm/arm64: KVM: Fix set_clear_sgi_pend_reg offset

From: Greg Kroah-Hartman
Date: Wed Jul 01 2015 - 14:48:16 EST


3.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Christoffer Dall <christoffer.dall@xxxxxxxxxx>

commit 0fea6d7628ed6e25a9ee1b67edf7c859718d39e8 upstream.

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@xxxxxxxxxx>
Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
Signed-off-by: Shannon Zhao <shannon.zhao@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
virt/kvm/arm/vgic.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -674,7 +674,7 @@ static bool read_set_clear_sgi_pend_reg(
{
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;
@@ -695,7 +695,7 @@ static bool write_set_clear_sgi_pend_reg
{
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;


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