Re: SUNRPC: Checking a kmemdup() call in xdr_netobj_dup()

From: Markus Elfring
Date: Tue Oct 15 2019 - 01:45:04 EST


>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/linux/sunrpc/xdr.h?id=1c0cc5f1ae5ee5a6913704c0d75a6e99604ee30a#n167
>> https://elixir.bootlin.com/linux/v5.4-rc2/source/include/linux/sunrpc/xdr.h#L167
>>
>> How do you think about to improve it?
>
> On a quick check--I see five xdr_netobj_dup callers, and all of them
> check whether dst->data is NULL.

Your information is appropriate.
https://elixir.bootlin.com/linux/v5.4-rc2/ident/xdr_netobj_dup

Such a Linux source code cross reference can point out that the function âxdr_netobj_dupâ
is used only within the source file âfs/nfsd/nfs4state.câ so far.


> Sounds like a false positive for your tool?

This depends on the software development view you would prefer here.
The desired null pointer checks are just not performed by the mentioned
(inline) function itself.
I imagine then that a dedicated macro might help to stress software design constraints.

Regards,
Markus