Re: Kernel strscpy() should be renamed to kstrscpy() Re: [PATCH] nfs_sysfs_link_rpc_client(): Replace strcpy with strscpy

[Benjamin Coddington]

On 9 Nov 2024, at 6:11, Sebastian Feld wrote:

> On Wed, Nov 6, 2024 at 9:40 PM Benjamin Coddington <bcodding@xxxxxxxxxx> wrote:
>>
>> On 6 Nov 2024, at 15:20, Roland Mainz wrote:
>>
>>> On Wed, Nov 6, 2024 at 3:49 AM Daniel Yang <danielyangkang@xxxxxxxxx> wrote:
>>>>
>>>> The function strcpy is deprecated due to lack of bounds checking. The
>>>> recommended replacement is strscpy.
>>>>
>>>> Signed-off-by: Daniel Yang <danielyangkang@xxxxxxxxx>
>>>> ---
>>>>  fs/nfs/sysfs.c | 2 +-
>>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/fs/nfs/sysfs.c b/fs/nfs/sysfs.c
>>>> index bf378ecd5..f3d0b2ef9 100644
>>>> --- a/fs/nfs/sysfs.c
>>>> +++ b/fs/nfs/sysfs.c
>>>> @@ -280,7 +280,7 @@ void nfs_sysfs_link_rpc_client(struct nfs_server *server,
>>>>         char name[RPC_CLIENT_NAME_SIZE];
>>>>         int ret;
>>>>
>>>> -       strcpy(name, clnt->cl_program->name);
>>>> +       strscpy(name, clnt->cl_program->name);
>>>
>>> How should the "bounds checking" work in this case if you only pass
>>> two arguments ?
>>
>> The linux kernel strscpy() checks the sizeof the destination.
>
> Then the kernel strscpy() should be renamed accordingly, and not
> confuse people. Suggested name would be kstrscpy().
> Otherwise this would disqualify strscpy() ever from being adopted as a
> POSIX standard, as there are two - kernel and glibc - conflicting
> implementations

I should have said the linux kernel strscpy() can accept only two args if
the destination is a statically-defined array.  Most uses are the three arg
version.

Ben