Re: [PATCH] RDMA/ocrdma: Fix an off-by-one issue in 'ocrdma_add_stat'

[Dan Carpenter]

On Tue, Apr 14, 2020 at 03:34:41PM -0300, Jason Gunthorpe wrote:
> The memcpy is still kind of silly right? What about this:
> 
> static int ocrdma_add_stat(char *start, char *pcur, char *name, u64 count)
> {
> 	size_t len = (start + OCRDMA_MAX_DBGFS_MEM) - pcur;
> 	int cpy_len;
> 
> 	cpy_len = snprintf(pcur, len, "%s: %llu\n", name, count);
> 	if (cpy_len >= len || cpy_len < 0) {

The kernel version of snprintf() doesn't and will never return
negatives.  It would cause a huge security headache if it started
returning negatives.

> 		pr_err("%s: No space in stats buff\n", __func__);
> 		return 0;
> 	}

regards,
dan carpenter