Re: [PATCH 01/11] params: bound array element output to the caller's page buffer

[Anshuman]

On Thu, May 21, 2026 at 06:33:14AM -0700, Kees Cook wrote:
> ret = min(ret, (int)(PAGE_SIZE - 1 - off));
> if (!ret)
> 	break;

One question about the truncation behavior here: when an element does
not fully fit in the remaining buffer, this min() can cause only part
of that element to be copied. For example, if the remaining space is
4 bytes and the next element produces "123456789\n", the resulting
output could contain only "1234".

This leaves the reader with no way to distinguish a genuinely short
value from one that was truncated due to the PAGE_SIZE limit, while
the array otherwise still looks like a normal comma-separated list.

Is this partial-element truncation intentional for this patch, or is
the expectation that it gets handled as part of the later seq_buf
conversion? Would it be preferable to avoid copying an element unless
it fits completely, and leave the larger-buffer case to be addressed
later in the series?