Re: [PATCH 2/2] mm/page_alloc: don't spin_trylock() when disallowed in free_one_page()

[Harry Yoo]

On 7/15/26 6:03 PM, Brendan Jackman wrote:
> __free_frozen_pages() checks can_spin_trylock() before entering into the
> main free_frozen_page_commit()/free_one_page() path, but before this it
> can get to free_one_page() via the !pcp_allowed_order() and
> MIGRATE_ISOLATE paths.
> 
> The !pcp_allowed_order() path depends on usage by callers so might not
> be possible in practice. The MIGRATE_ISOLATE path probably means kernel
> crashes and privilege escalation if anyone ever did memory hotplug and
> BPF tracing on a PREEMPT_RT or !SMP build.
> 
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 8c57b687e8331 ("mm, bpf: Introduce free_pages_nolock()")
> Reported-by: sashiko-bot@xxxxxxxxxx
> Link: https://sashiko.dev/#/patchset/20260710-spin-trylock-followup-v1-0-affb5fe5ed00%40google.com?part=2
> Signed-off-by: Brendan Jackman <jackmanb@xxxxxxxxxx>
> ---

Looks good to me, so:
Reviewed-by: Harry Yoo (Oracle) <harry@xxxxxxxxxx>

-- 
Cheers,
Harry / Hyeonggon

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