Re: [RFC PATCH 1/2] mm/damon/reclaim: handle ctx allocation failure

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] The patch prevents loading the damon_reclaim module with the 'enabled=Y' parameter by returning -ENOMEM during parameter parsing.
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commit d55c0d692febe0a6f116ac49f1c1187ff2f47d7b
Author: SeongJae Park <sj@kernel.org>
mm/damon/reclaim: handle ctx allocation failure

This commit adds a check in damon_reclaim_enabled_store() to return -ENOMEM
if the ctx pointer is NULL. This is intended to prevent a NULL pointer
dereference if the context allocation failed during initialization.

Cc: stable@vger.kernel.org # 6.18.x

> diff --git a/mm/damon/reclaim.c b/mm/damon/reclaim.c
> index ed446d00ef1cf..ce4499cf4b8b0 100644
> --- a/mm/damon/reclaim.c
> +++ b/mm/damon/reclaim.c
> @@ -399,6 +399,10 @@ static int damon_reclaim_enabled_store(const char *val,
>  	if (!damon_initialized())
>  		return 0;
>  
> +	/* damon_modules_new_paddr_ctx_target() in the init function failed. */
> +	if (!ctx)
> +		return -ENOMEM;
> +

[Severity: High]
When the damon_reclaim module is loaded with the enabled=Y parameter,
load_module() calls parse_args() before running the module's
damon_reclaim_init() function. At this point, damon_initialized()
returns true since the damon core is already initialized, but ctx is
still NULL.

Will this new check return -ENOMEM and abort the entire module loading
process during parameter parsing instead of successfully loading?

>  	return damon_reclaim_turn(enabled);
>  }

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Sashiko AI review · https://sashiko.dev/#/patchset/20260528061110.2172-1-sj@kernel.org?part=1