[PATCH] nvme-pci: fix dma mapping leak on data setup error

[Keith Busch]

On Tue, May 19, 2026 at 01:06:14PM -0700, Keith Busch wrote:
> -	if (!nvme_pci_prp_save_mapping(req, nvmeq->dev->dev, iter))
> +	if (!nvme_pci_prp_save_mapping(req, nvmeq->dev->dev, iter)) {
> +		dma_unmap_phys(nvmeq->dev->dev, iter->addr, iter->len,
> +			       rq_dma_dir(req),
> +			       iod->flags & IOD_DATA_MMIO ? DMA_ATTR_MMIO : 0);
>  		return iter->status;
> +	}
>  
>  	/*
>  	 * PRP1 always points to the start of the DMA transfers.
> @@ -1112,6 +1116,7 @@ static blk_status_t nvme_pci_setup_data_prp(struct request *req,
>  	dev_err_once(nvmeq->dev->dev,
>  		"Incorrectly formed request for payload:%d nents:%d\n",
>  		blk_rq_payload_bytes(req), blk_rq_nr_phys_segments(req));
> +	nvme_unmap_data(req);
>  	return BLK_STS_IOERR;
>  }
>  
> @@ -1155,8 +1160,13 @@ static blk_status_t nvme_pci_setup_data_sgl(struct request *req,
>  
>  	sg_list = dma_pool_alloc(nvme_dma_pool(nvmeq, iod), GFP_ATOMIC,
>  			&sgl_dma);
> -	if (!sg_list)
> +	if (!sg_list) {
> +		dma_unmap_phys(nvmeq->dev->dev, iter->addr, iter->len,
> +			       rq_dma_dir(req),
> +			       iod->flags & IOD_DATA_MMIO ? DMA_ATTR_MMIO : 0);
>  		return BLK_STS_RESOURCE;
> +	}

Oh, these need to check dma_need_unmap() first. I'll send a v2.