[PATCH kernel v7 16/20] powerpc/powernv/npu: Check mmio_atsd array bounds when populating

Alexey Kardashevskiy
2018-12-20T08:23:46Z

A broken device tree might contain more than 8 values and introduce hard
to debug memory corruption bug. This adds the boundary check.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
arch/powerpc/platforms/powernv/npu-dma.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/npu-dma.c b/arch/powerpc/platforms/powernv/npu-dma.c
index e06043b..c6163b9 100644
--- a/arch/powerpc/platforms/powernv/npu-dma.c
+++ b/arch/powerpc/platforms/powernv/npu-dma.c
@@ -1179,8 +1179,9 @@ int pnv_npu2_init(struct pci_controller *hose)

npu->nmmu_flush = of_property_read_bool(hose->dn, "ibm,nmmu-flush");

- for (i = 0; !of_property_read_u64_index(hose->dn, "ibm,mmio-atsd",
- i, &mmio_atsd); i++)
+ for (i = 0; i < ARRAY_SIZE(npu->mmio_atsd_regs) &&
+ !of_property_read_u64_index(hose->dn, "ibm,mmio-atsd",
+ i, &mmio_atsd); i++)
npu->mmio_atsd_regs[i] = ioremap(mmio_atsd, 32);

pr_info("NPU%d: Found %d MMIO ATSD registers", hose->global_number, i);
--
2.17.1