Re: [PATCH] MIPS: CPS: Fix potential NULL pointer dereferences in cps_prepare_cpus()

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

On Mon, Apr 07, 2025 at 06:32:21PM +0200, Thorsten Blum wrote:
> Check the return values of kcalloc() and exit early to avoid potential
> NULL pointer dereferences.
> 
> Compile-tested only.
> 
> Cc: stable@vger.kernel.org
> Fixes: 75fa6a583882e ("MIPS: CPS: Introduce struct cluster_boot_config")
> Fixes: 0856c143e1cd3 ("MIPS: CPS: Boot CPUs in secondary clusters")
> Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
> ---
>  arch/mips/kernel/smp-cps.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/arch/mips/kernel/smp-cps.c b/arch/mips/kernel/smp-cps.c
> index e85bd087467e..cc26d56f3ab6 100644
> --- a/arch/mips/kernel/smp-cps.c
> +++ b/arch/mips/kernel/smp-cps.c
> @@ -332,6 +332,8 @@ static void __init cps_prepare_cpus(unsigned int max_cpus)
>  	mips_cps_cluster_bootcfg = kcalloc(nclusters,
>  					   sizeof(*mips_cps_cluster_bootcfg),
>  					   GFP_KERNEL);
> +	if (!mips_cps_cluster_bootcfg)
> +		goto err_out;
>  
>  	if (nclusters > 1)
>  		mips_cm_update_property();
> @@ -348,6 +350,8 @@ static void __init cps_prepare_cpus(unsigned int max_cpus)
>  		mips_cps_cluster_bootcfg[cl].core_power =
>  			kcalloc(BITS_TO_LONGS(ncores), sizeof(unsigned long),
>  				GFP_KERNEL);
> +		if (!mips_cps_cluster_bootcfg[cl].core_power)
> +			goto err_out;
>  
>  		/* Allocate VPE boot configuration structs */
>  		for (c = 0; c < ncores; c++) {
> -- 
> 2.49.0

applied to mips-fixes.

Thomas.

-- 
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