Re: [PATCH bpf-next 1/2] bpf: Account for preempt and IRQ state in RCU protection

[Eduard Zingerman]

On Wed, 2026-08-05 at 16:39 -0700, Ning Ding wrote:
> Disabling preemption or local IRQs keeps the current CPU in an RCU
> read-side critical section, but in_rcu_cs() does not account for either
> state. The verifier therefore rejects safe kptr accesses and invalidates
> pointers when another RCU source ends.
> 
> Include preemption-disabled and IRQ-disabled state in in_rcu_cs().
> Invalidate RCU-protected pointers on RCU unlock, preempt enable, or IRQ
> restore only after the final protection ends.
> 
> Signed-off-by: Ning Ding <dingning04@xxxxxxxxx>
> ---

Hi Ning,

Thank you for identifying and fixing this issue!

Acked-by: Eduard Zingerman <eddyz87@xxxxxxxxx>

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