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

[SJ Park <sj@kernel.org>]

On Thu, 09 Jul 2026 14:36:51 +0000 sashiko-bot@kernel.org wrote:

> Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> - [Low] Spelling mistake in comment.
> --
> 
> --- 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").

Good finding.  I will fix in the next revision.

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


Thanks,
SJ