Re: [RFC PATCH v1.2 10/19] mm/damon/core: validate params for probe hits weighted sum overflow

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] Spelling mistake in comment.
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--- Patch [10]: [RFC PATCH v1.2 10/19] mm/damon/core: validate params for probe hits weighted sum overflow ---
commit 3e76c3dde55500288f3eccb730acd26964bfdad2
Author: SJ Park <sj@kernel.org>

mm/damon/core: validate params for probe hits weighted sum overflow

This commit adds parameter validation to prevent probe hits weighted sum
overflow. It ensures that the combination of probe weights and aggregation
intervals does not exceed the maximum allowed values.

> diff --git a/mm/damon/core.c b/mm/damon/core.c
> index 4f1425e56950b..b585e4bf035f1 100644
> --- a/mm/damon/core.c
> +++ b/mm/damon/core.c
[ ... ]
> @@ -1342,6 +1345,18 @@ static bool damon_valid_probe_params(struct damon_ctx *ctx)
>  	sample_interval = ctx->attrs.sample_interval ? : 1;
>  	if (ctx->attrs.aggr_interval / sample_interval > U8_MAX)
>  		return false;
> +
> +	/* invlaid if probe hits weighted sum can overflow */

[Severity: Low]
This isn't a bug, but there is a typo in this comment ("invlaid" instead of
"invalid").

> +	max_probe_hits = damon_nr_samples_per_aggr(&ctx->attrs);
> +	wsum = 0;
> +	damon_for_each_probe(probe, ctx) {
> +		if (probe->weight > UINT_MAX / max_probe_hits)
> +			return false;
> +		wsum_to_add = probe->weight * max_probe_hits;
> +		if (UINT_MAX - wsum < wsum_to_add)
> +			return false;
> +		wsum += wsum_to_add;
> +	}
>  	return true;
>  }

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Sashiko AI review · https://sashiko.dev/#/patchset/20260709140600.90950-1-sj@kernel.org?part=10