Messages in this thread | | | Date | Tue, 26 Oct 2021 19:33:09 +0300 | From | "" <> | Subject | Re: suspected null-pointer-reference problem for to_swnode |
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On Tue, Oct 26, 2021 at 06:11:57PM +0300, Sakari Ailus wrote: > On Mon, Oct 25, 2021 at 07:40:55PM +0300, andriy.shevchenko@linux.intel.com wrote: > > On Mon, Oct 25, 2021 at 02:03:51PM +0000, YE Chengfeng wrote: > > > Hi, > > > > > > https://github.com/torvalds/linux/blob/master/drivers/base/swnode.c#L405 > > > > > > We notice that the return pointer of to_swnode is null check in some case, while in some case is not. For example, at line 416, the return pointer is null-check, but in line 405 is not. We want to know whether it would be a potential null pointer dereference problem, in the case that null-check is missing. > > > > > > This problem is detected by our experimental static analysis tool, we are not familiar with the source code and it could just be a false positive. We send this email in case this is a real problem. Would you like to spare some time to have a look at it? > > > > Thank you for the interest to our code! > > > > Line #405 refers to software node operations and it means it won't be ever > > called if there is no swnode behind it, means it's backed with properties. > > If you think it will be a NULL pointer there, please describe in detail > > (with a traceback included) when and how it happens, because such bugs are > > serious. > > > > Line #416 refers to the same stage when options are defined and we know we > > have been called against swnode. Seems to me like a dead code brought from > > day 1 by the commit bc0500c1e43d ("device property: Add fwnode_get_name > > for returning the name of a node"). > > > > Sakari? > > Yeah, the check could be removed.
I have just sent a patch.
-- With Best Regards, Andy Shevchenko
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