Re: [PATCH] iommu: add null pointer check

[Joerg Roedel]

On Tue, Mar 29, 2022 at 05:53:22AM +0000, cgel.zte@xxxxxxxxx wrote:
> From: Lv Ruyi <lv.ruyi@xxxxxxxxxx>
> 
> kmem_cache_zalloc is a memory allocation function which can return NULL
> when some internal memory errors happen. Add null pointer check to avoid
> dereferencing null pointer.
> 
> Reported-by: Zeal Robot <zealci@xxxxxxxxxx>
> Signed-off-by: Lv Ruyi <lv.ruyi@xxxxxxxxxx>
> ---
>  drivers/iommu/fsl_pamu_domain.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/iommu/fsl_pamu_domain.c b/drivers/iommu/fsl_pamu_domain.c
> index 69a4a62dc3b9..43849c027298 100644
> --- a/drivers/iommu/fsl_pamu_domain.c
> +++ b/drivers/iommu/fsl_pamu_domain.c
> @@ -152,6 +152,10 @@ static void attach_device(struct fsl_dma_domain *dma_domain, int liodn, struct d
>  	}
>  
>  	info = kmem_cache_zalloc(iommu_devinfo_cache, GFP_ATOMIC);
> +	if (!info) {
> +		spin_unlock_irqrestore(&device_domain_lock, flags);
> +		return;
> +	}

Such errors need to be propagated.