Re: [PATCH] MIPS: SB1250: Validate and update IRQ affinity

[Thomas Bogendoerfer <tsbogend@alpha.franken.de>]

On Tue, Nov 03, 2026 at 01:50:40PM -0800, Florian Fainelli wrote:
> sb1250_set_affinity() selects the first online CPU in the requested
> affinity mask without checking whether such a CPU exists. If the
> intersection is empty, the resulting CPU index is invalid and must
> not be passed to cpu_logical_map().
> 
> Reject affinity masks containing no online CPU with -EINVAL before
> accessing the CPU mapping or interrupt mapper registers.
> 
> Also update the effective affinity mask to reflect the single logical
> CPU selected as the interrupt target.
> 
> Fixes: 421d1563c662 ("mips: Validate online cpus in irq_set_affinity() callbacks")
> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
> ---
>  arch/mips/sibyte/sb1250/irq.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/arch/mips/sibyte/sb1250/irq.c b/arch/mips/sibyte/sb1250/irq.c
> index 2f08ad267a11..d7a656cd7ec0 100644
> --- a/arch/mips/sibyte/sb1250/irq.c
> +++ b/arch/mips/sibyte/sb1250/irq.c
> @@ -76,6 +76,8 @@ static int sb1250_set_affinity(struct irq_data *d, const struct cpumask *mask,
>  	unsigned long flags;
>  
>  	i = cpumask_first_and(mask, cpu_online_mask);
> +	if (i >= nr_cpu_ids)
> +		return -EINVAL;
>  
>  	/* Convert logical CPU to physical CPU */
>  	cpu = cpu_logical_map(i);
> @@ -103,6 +105,7 @@ static int sb1250_set_affinity(struct irq_data *d, const struct cpumask *mask,
>  		____raw_writeq(cur_ints, IOADDR(A_IMR_MAPPER(cpu) +
>  					R_IMR_INTERRUPT_MASK));
>  	}
> +	irq_data_update_effective_affinity(d, cpumask_of(i));
>  	raw_spin_unlock_irqrestore(&sb1250_imr_lock, flags);
>  
>  	return 0;
> -- 
> 2.53.0

applied to mips-fixes

Thomas.

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