Re: [LTP] fsx-linux: Fix reference buffer corruption in op_map_read()

[linuxtestproject.agent@gmail.com]

Hi Jinseok,

On Tue, 18 Aug 2026, Jinseok Kim wrote:
> fsx-linux: Fix reference buffer corruption in op_map_read()

--- [PATCH 2/2] ---

> +	max_len = fsize - pos->offset;
> +	if (max_len > op_max_size)
> +		max_len = op_max_size;
> +
> +	pos->size = random() % max_len;
>
> 	diff = pos->offset % align;
>
> 	if (diff) {
> 		pos->offset -= diff;
> 		pos->size += diff;
> 	}

Could the offset be aligned before max_len is calculated, or could the final
size be capped after alignment?

The new cap bounds pos->size only before offset % align is added back. With
-o 1 -w 4096, pos->size starts at zero and can then grow to 4095 bytes, so
-o still is not an upper bound. This also affects the existing fsx05 entry,
which combines -o 1024 with -w 4096.

Verdict - Needs revision

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