[lvc-project] [PATCH] remoteproc: imx_rproc: Adjust phandle parsing issue while remapping optional addresses in imx_rproc_addr_init()

[Aleksandr Mishin]

On 11.06.2024 19:45, Mathieu Poirier wrote:
> On Mon, Jun 10, 2024 at 08:36:19PM +0300, Fedor Pchelkin wrote:
>> On Mon, 10. Jun 10:47, Mathieu Poirier wrote:
>>> On Thu, Jun 06, 2024 at 10:52:04AM +0300, Aleksandr Mishin wrote:
>>>> In imx_rproc_addr_init() "nph = of_count_phandle_with_args()" just counts
>>>> number of phandles. But phandles may be empty. So of_parse_phandle() in
>>>> the parsing loop (0 < a < nph) may return NULL which is later dereferenced.
>>>> Adjust this issue by adding NULL-return check.
>>>>
>>>> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>>>>
>>>> Fixes: a0ff4aa6f010 ("remoteproc: imx_rproc: add a NXP/Freescale imx_rproc driver")
>>>> Signed-off-by: Aleksandr Mishin <amishin at t-argos.ru>
>>>> ---
>>>>   drivers/remoteproc/imx_rproc.c | 2 ++
>>>>   1 file changed, 2 insertions(+)
>>>>
>>>> diff --git a/drivers/remoteproc/imx_rproc.c b/drivers/remoteproc/imx_rproc.c
>>>> index 5a3fb902acc9..39eacd90af14 100644
>>>> --- a/drivers/remoteproc/imx_rproc.c
>>>> +++ b/drivers/remoteproc/imx_rproc.c
>>>> @@ -726,6 +726,8 @@ static int imx_rproc_addr_init(struct imx_rproc *priv,
>>>>   		struct resource res;
>>>>   
>>>>   		node = of_parse_phandle(np, "memory-region", a);
>>>> +		if (!node)
>>>
>>> You're missing an "of_node_put()" before continuing.
>>>
>>
>> The node is NULL in this case so of_node_put() is not needed..?
> 
> Oh yeah, doing a of_node_put() with a NULL value is are really good idea...
> 
> I will pickup this patch.
> 
>>
>> Btw, there is a "rsc-table" node->name check in the the end of the loop
>> body. It was added recently with commit 5e4c1243071d ("remoteproc:
>> imx_rproc: support remote cores booted before Linux Kernel"). Seems to me
>> it forgot that of_node_put() is called way before that.
>>
> 
> I agree.
> 
>> Also commit 61afafe8b938 ("remoteproc: imx_rproc: Fix refcount leak in
>> imx_rproc_addr_init") was dealing with the last of_node_put() call here
>> but it's still not in the right place I'd say.
>>
> 
> You mean becaue of node->name being used after the last of_node_put() or is
> there something else?
> 
> Aleksandr - Can you send another patch for the above?

Patch is sent.
https://lore.kernel.org/all/20240612131714.12907-1-amishin@t-argos.ru/

> 
> Thanks,
> Mathieu
> 
>>>> +			continue;
>>>>   		/* Not map vdevbuffer, vdevring region */
>>>>   		if (!strncmp(node->name, "vdev", strlen("vdev"))) {
>>>>   			of_node_put(node);
>>>> -- 
>>>> 2.30.2
>>>>
>>>>

-- 
Kind regards
Aleksandr