Re: [PATCH v2 0/2] cpufreq: acpi-cpufreq: fix P-state index mismatch in freq lookups

[Zhongqiu Han]

On 8/13/2026 5:01 PM, lirongqing wrote:
> From: Li RongQing <lirongqing@xxxxxxxxx>
>
> policy->freq_table is built with duplicate _PSS frequencies dropped, so it
> no longer lines up positionally with perf->states[]; the original P-state
> index is kept in freq_table[].driver_data. extract_io() and
> get_cur_freq_on_cpu() indexed freq_table[] with a perf->states[] index
> anyway, which can return the frequency of a wrong P-state.
>
> Changes since v1:
> - Reword patch 1: v1 described it as an out-of-bounds read, which is wrong;
>    it is an index-mismatch / wrong-result bug, not a memory-safety issue.
> - Add patch 2 for get_cur_freq_on_cpu().
> - Add Fixes: tags (not exact, but reasonable backport targets).

Hi RongQing,

The Fixes tag should point to the commit that introduced the bug.

> Li RongQing (2):
>    cpufreq: acpi-cpufreq: fix P-state index mismatch in extract_io()
>    cpufreq: acpi-cpufreq: fix P-state index mismatch in
>      get_cur_freq_on_cpu()
>
>   drivers/cpufreq/acpi-cpufreq.c | 18 ++++++++++++------
>   1 file changed, 12 insertions(+), 6 deletions(-)


--
Thx and BRs,
Zhongqiu Han