On 5/18/2016 3:58 PM, Rhyland Klein wrote:
> On 5/18/2016 3:36 PM, Rob Herring wrote:
>> 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;
>>
>
> If I try that patch, i see this when compiling:
>
> In function ‘unflatten_dt_nodes’:
> warning: left-hand operand of comma expression has no effect
> [-Wunused-value]
> offset >= 0, depth >= 0;
>
This patch seems to work for me. I found a bug in my original patch.
Sasha/Rob, can you see if this works for you too:
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 0b5850027bb5..e7a8caac5b27 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -407,9 +407,9 @@ static int unflatten_dt_nodes(const void *blob,
root = dad;
fpsizes[depth] = dad ? strlen(of_node_full_name(dad)) : 0;
- nps[depth+1] = dad;
+ nps[depth] = 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;
-rhyland
--
nvpublic
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