Re: [PATCH 01/16] irqchip/riscv-imsic: fix MMIO lookup OOB and NULL cleanup

[Radu Rendec <radu@rendec.net>]

On Tue, 2026-07-14 at 20:23 +0800, Haofeng Li wrote:
> The MSI page lookup loop uses:
> 
> 	for (j = 0; nr_mmios; j++)
> 
> When nr_mmios is non-zero the condition is always true, so j is never
> bounded. If reloff does not fall in any MMIO region the loop indexes
> past mmios[] and may hang or fault.
> 
> Also, mmios_va starts as NULL. If its allocation fails, the out_iounmap
> path indexes mmios_va[i] and NULL-dereferences.
> 
> Bound the loop with j < nr_mmios, and guard the iounmap/kfree cleanup
> with if (mmios_va).
> 
> Fixes: 21a8f8a0eb35 ("irqchip: Add RISC-V incoming MSI controller early driver")
> Signed-off-by: Haofeng Li <lihaofeng@kylinos.cn>
> ---
>  drivers/irqchip/irq-riscv-imsic-state.c | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/irqchip/irq-riscv-imsic-state.c b/drivers/irqchip/irq-riscv-imsic-state.c
> index b8d1bbbf42f7..19f74cf79988 100644
> --- a/drivers/irqchip/irq-riscv-imsic-state.c
> +++ b/drivers/irqchip/irq-riscv-imsic-state.c
> @@ -896,7 +896,7 @@ int __init imsic_setup_state(struct fwnode_handle *fwnode, void *opaque)
>  		index = nr_mmios;
>  		reloff = i * BIT(global->guest_index_bits) *
>  			 IMSIC_MMIO_PAGE_SZ;
> -		for (j = 0; nr_mmios; j++) {
> +		for (j = 0; j < nr_mmios; j++) {
>  			if (reloff < resource_size(&mmios[j])) {
>  				index = j;
>  				break;
> @@ -953,11 +953,13 @@ int __init imsic_setup_state(struct fwnode_handle *fwnode, void *opaque)
>  out_local_cleanup:
>  	imsic_local_cleanup();
>  out_iounmap:
> -	for (i = 0; i < nr_mmios; i++) {
> -		if (mmios_va[i])
> -			iounmap(mmios_va[i]);
> +	if (mmios_va) {
> +		for (i = 0; i < nr_mmios; i++) {
> +			if (mmios_va[i])
> +				iounmap(mmios_va[i]);
> +		}
> +		kfree(mmios_va);
>  	}
> -	kfree(mmios_va);
>  	kfree(mmios);
>  out_free_local:
>  	free_percpu(imsic->global.local);

Reviewed-by: Radu Rendec <radu@rendec.net>