Re: [PATCH next] drivers/block/rbd: Use strscpy() to copy strings into arrays

[Alex Elder <elder@ieee.org>]

On 6/6/26 3:27 PM, david.laight.linux@gmail.com wrote:
> From: David Laight <david.laight.linux@gmail.com>
> 
> Replacing strcpy() with strscpy() ensures than overflow of the target
> buffer cannot happen.
> 
> Signed-off-by: David Laight <david.laight.linux@gmail.com>
> ---
> This is one of a group of patches that remove potentially unbounded
> strcpy() calls.
> 
> They are mostly replaced by strscpy() or, when strlen() has just been
> called, with memcpy() (usually including the '\0').
> 
> Calls with copy string literals into arrays are left unchanged.
> They are safe and easily detected as such.
> 
> The changes were made by getting the compiler to detect the calls and
> then fixing the code by hand.
> 
> Note that all the changes are only compile tested.
> 
> Some Makefiles were changed to allow files to contain strcpy().
> As well as 'difficult to fix' files, this included 'show' functions
> as they really need to use sysfs_emit() or seq_printf().
> 
> All the patches are being sent individually to avoid very long cc lists.
> Apologies for the terse commit messages and likely unexpected tags.
> (There are about 100 patches in total.)
> 
>   drivers/block/rbd.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
> index 4065336ebd1f..632fa2d56ea0 100644
> --- a/drivers/block/rbd.c
> +++ b/drivers/block/rbd.c
> @@ -3672,7 +3672,7 @@ static void __rbd_lock(struct rbd_device *rbd_dev, const char *cookie)
>   	struct rbd_client_id cid = rbd_get_cid(rbd_dev);
>   
>   	rbd_dev->lock_state = RBD_LOCK_STATE_LOCKED;
> -	strcpy(rbd_dev->lock_cookie, cookie);
> +	strscpy(rbd_dev->lock_cookie, cookie);

This looks good.  The rbd_device->lock_cookie is a 32 byte
array.

Cookies passed in are always a 32 byte array (despite the
function only requiring a string pointer).

Reviewed-by: Alex Elder <elder@riscstar.com>

>   	rbd_set_owner_cid(rbd_dev, &cid);
>   	queue_work(rbd_dev->task_wq, &rbd_dev->acquired_lock_work);
>   }