Re: drivers/of: crash on boot

[Rob Herring]

On Wed, May 18, 2016 at 10:34 AM, Sasha Levin <sasha.levin@xxxxxxxxxx> wrote:
> Hi Rhyland,
>
> I'm seeing a crash on boot that seems to have been caused by
> "drivers/of: Fix depth when unflattening devicetree":
>
> [   61.145229] ==================================================================
>
> [   61.147588] BUG: KASAN: stack-out-of-bounds in unflatten_dt_nodes+0x11d2/0x1290 at addr ffff88005b30777c

The following appears to fix it for me. Rhyland, please confirm.

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 7f38241..888ec2a 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -409,7 +409,7 @@ static int unflatten_dt_nodes(const void *blob,
        fpsizes[depth] = dad ? strlen(of_node_full_name(dad)) : 0;
        nps[depth+1] = dad;
        for (offset = 0;
-            offset >= 0;
+            offset >= 0, depth >= 0;
             offset = fdt_next_node(blob, offset, &depth)) {
                if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH))
                        continue;