Re: [PATCH v3 06/11] dmaengine: switchtec-dma: fix chan_status_irq cleanup on create() error

[Frank Li]

On Mon, Jul 27, 2026 at 12:15:21PM -0600, Logan Gunthorpe wrote:
> chan_status_irq stores an MSI-X vector index, but err_exit freed it
> with plain free_irq() instead of pci_free_irq(), which would free the
> wrong Linux IRQ. The guard also treated a valid vector index of 0 as
> unset, skipping the free entirely in that case and leaving the handler
> registered against soon-to-be-freed swdma_dev.
>
> Initialize chan_status_irq to -1 and use the value being non-negative
> to signal when to free it with pci_free_irq().
>
> Reported-by: Sashiko <sashiko-bot@xxxxxxxxxx>
> Link: https://lore.kernel.org/dmaengine/20260717223431.625EE1F000E9@xxxxxxxxxxxxxxx
> Signed-off-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
> ---

Reviewed-by: Frank Li <Frank.Li@xxxxxxx>

>  drivers/dma/switchtec_dma.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/dma/switchtec_dma.c b/drivers/dma/switchtec_dma.c
> index c752a1b05871..31feb2816e79 100644
> --- a/drivers/dma/switchtec_dma.c
> +++ b/drivers/dma/switchtec_dma.c
> @@ -1248,6 +1248,8 @@ static int switchtec_dma_create(struct pci_dev *pdev)
>  	if (!swdma_dev)
>  		return -ENOMEM;
>
> +	swdma_dev->chan_status_irq = -1;
> +
>  	swdma_dev->bar = ioremap(pci_resource_start(pdev, 0),
>  				 pci_resource_len(pdev, 0));
>
> @@ -1322,8 +1324,8 @@ static int switchtec_dma_create(struct pci_dev *pdev)
>  	switchtec_dma_chans_free(swdma_dev);
>
>  err_exit:
> -	if (swdma_dev->chan_status_irq)
> -		free_irq(swdma_dev->chan_status_irq, swdma_dev);
> +	if (swdma_dev->chan_status_irq >= 0)
> +		pci_free_irq(pdev, swdma_dev->chan_status_irq, swdma_dev);
>
>  	iounmap(swdma_dev->bar);
>  	kfree(swdma_dev);
> --
> 2.47.3
>