[PATCH 4.0 067/105] MIPS: KVM: Do not sign extend on unsigned MMIO load

From: Greg Kroah-Hartman
Date: Fri Jun 19 2015 - 17:11:05 EST

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


From: Nicholas Mc Guire <hofrat@xxxxxxxxx>

commit ed9244e6c534612d2b5ae47feab2f55a0d4b4ced upstream.

Fix possible unintended sign extension in unsigned MMIO loads by casting
to uint16_t in the case of mmio_needed != 2.

Signed-off-by: Nicholas Mc Guire <hofrat@xxxxxxxxx>
Reviewed-by: James Hogan <james.hogan@xxxxxxxxxx>
Tested-by: James Hogan <james.hogan@xxxxxxxxxx>
Cc: Gleb Natapov <gleb@xxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: kvm@xxxxxxxxxxxxxxx
Cc: linux-mips@xxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Patchwork: https://patchwork.linux-mips.org/patch/9985/
Signed-off-by: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

arch/mips/kvm/emulate.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/mips/kvm/emulate.c
+++ b/arch/mips/kvm/emulate.c
@@ -2101,7 +2101,7 @@ enum emulation_result kvm_mips_complete_
if (vcpu->mmio_needed == 2)
*gpr = *(int16_t *) run->mmio.data;
- *gpr = *(int16_t *) run->mmio.data;
+ *gpr = *(uint16_t *)run->mmio.data;

case 1:

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
Please read the FAQ at http://www.tux.org/lkml/