Re: [PATCH] sched/mmcid: Don't assume CID is CPU owned on mode switch

[Mathieu Desnoyers]

On 2026-02-10 11:20, Thomas Gleixner wrote:
> Shinichiro reported a KASAN UAF, which is actually an out of bounds access
> in the MMCID management code.
[...]
> Fixes: 007d84287c74 ("sched/mmcid: Drop per CPU CID immediately when switching to per task mode")
> Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@xxxxxxx>
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxx>
> Tested-by: Shinichiro Kawasaki <shinichiro.kawasaki@xxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> Closes: https://lore.kernel.org/aYsZrixn9b6s_2zL@shinmob
> ---
>
> Linus, can you please take that directly?

Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>

--
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com