2021-10-25 15:27:33

by YE Chengfeng

Subject: driver/bug: suspected missing null check in hisi_lpc.c

Hi,

https://github.com/torvalds/linux/blob/master/drivers/bus/hisi_lpc.c#L483

Our experimental static analysis tool detects a null-ptr-reference problem. It could be false positive, we report this to you just in case.

Null check is missing for the return pointer of ACPI_COMPANION at line 483 and line 504. It seems that there could be potential null-ptr-dereference problem at line 488 and line 509. Could you spare some time to have a look at it?

Thanks so much,
Chengfeng

2021-10-25 15:34:37

by YE Chengfeng

Subject: 回复: driver/bug: suspected missing null chec k in hisi_lpc.c

It is driver/bus, sorry for the typo.

-----?ʼ?ԭ??-----
??????: YE Chengfeng
????ʱ??: 2021??10??25?? 23:22
?ռ???: [email protected]; [email protected]
????: driver/bug: suspected missing null check in hisi_lpc.c

Hi,

https://github.com/torvalds/linux/blob/master/drivers/bus/hisi_lpc.c#L483

Our experimental static analysis tool detects a null-ptr-reference problem. It could be false positive, we report this to you just in case.

Null check is missing for the return pointer of ACPI_COMPANION at line 483 and line 504. It seems that there could be potential null-ptr-dereference problem at line 488 and line 509. Could you spare some time to have a look at it?

Thanks so much,
Chengfeng

2021-10-26 13:55:34

by John Garry

Subject: Re: 回复: driver/bug: suspected missing null check in hisi_lpc.c

On 25/10/2021 16:31, YE Chengfeng wrote:
> It is driver/bus, sorry for the typo.
>
> -----?ʼ?ԭ??-----
> ??????: YE Chengfeng
> ????ʱ??: 2021??10??25?? 23:22
> ?ռ???: [email protected]; [email protected]
> ????: driver/bug: suspected missing null check in hisi_lpc.c
>
> Hi,
>
> https://github.com/torvalds/linux/blob/master/drivers/bus/hisi_lpc.c#L483
>
> Our experimental static analysis tool detects a null-ptr-reference problem. It could be false positive, we report this to you just in case.
>
> Null check is missing for the return pointer of ACPI_COMPANION at line 483 and line 504. It seems that there could be potential null-ptr-dereference problem at line 488 and line 509. Could you spare some time to have a look at it?
>
> Thanks so much,
> Chengfeng
>

I don't think that we should have a problem as ACPI_COMPANION() should
just not return NULL for us. But I can't give you a better reason than
that without fully examining the ACPI code, which I'm not keen on...

Thanks,
John

2021-10-26 16:15:42

by YE Chengfeng

Subject: 回复: 回复: driver/bug: suspected missing nul l check in hisi_lpc.c

Thanks for your reply.

You are right. I found that null-check is already performed in the caller of this two function. Sorry for the bothering.

Best Regards,
Chengfeng

-----?ʼ?ԭ??-----
??????: John Garry <[email protected]>
????ʱ??: 2021??10??26?? 18:33
?ռ???: YE Chengfeng <[email protected]>; [email protected]
????: Re: ?ظ?: driver/bug: suspected missing null check in hisi_lpc.c

On 25/10/2021 16:31, YE Chengfeng wrote:
> It is driver/bus, sorry for the typo.
>
> -----?ʼ?ԭ??-----
> ??????: YE Chengfeng
> ????ʱ??: 2021??10??25?? 23:22
> ?ռ???: [email protected]; [email protected]
> ????: driver/bug: suspected missing null check in hisi_lpc.c
>
> Hi,
>
> https://apc01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgith
> ub.com%2Ftorvalds%2Flinux%2Fblob%2Fmaster%2Fdrivers%2Fbus%2Fhisi_lpc.c
> %23L483&amp;data=04%7C01%7Ccyeaa%40connect.ust.hk%7Cc26f0b4a52504737c2
> 7508d9986bf5ae%7C6c1d415239d044ca88d9b8d6ddca0708%7C1%7C0%7C6377084117
> 14447677%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiL
> CJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdata=lkx93QoK%2FN1ilG0u5il5l
> hVjUiAbVY6RX%2FuJh%2BBHmuI%3D&amp;reserved=0
>
> Our experimental static analysis tool detects a null-ptr-reference problem. It could be false positive, we report this to you just in case.
>
> Null check is missing for the return pointer of ACPI_COMPANION at line 483 and line 504. It seems that there could be potential null-ptr-dereference problem at line 488 and line 509. Could you spare some time to have a look at it?
>
> Thanks so much,
> Chengfeng
>

I don't think that we should have a problem as ACPI_COMPANION() should just not return NULL for us. But I can't give you a better reason than that without fully examining the ACPI code, which I'm not keen on...

Thanks,
John