Re: [PATCH net-next v2] octeontx2-af: Fix PCI device reference leaks in debugfs

[Jakub Kicinski]

On Mon,  8 Jun 2026 12:55:46 -0400 Yuho Choi wrote:
> cgx_print_stats(), cgx_print_dmac_flt(), and cgx_print_fwdata()
> look up the RVU AF device with pci_get_device() and pass the returned
> pointer directly to pci_get_drvdata().  pci_get_device() returns a PCI
> device with an elevated reference count, so the lookup reference is
> leaked on every debugfs read.
> 
> Store the returned PCI device pointer, check it before reading driver
> data, and release the lookup reference after pci_get_drvdata(). In
> cgx_print_dmac_flt(), release the AF lookup reference before reusing
> pdev for pci_get_domain_bus_and_slot().
> 
> Fixes: f967488d095e ("octeontx2-af: Add per CGX port level NIX Rx/Tx counters")
> Fixes: dbc52debf95f ("octeontx2-af: Debugfs support for DMAC filters")
> Fixes: 49f02e6877d1 ("Octeontx2-af: Debugfs support for firmware data")
> Signed-off-by: Yuho Choi <dbgh9129@xxxxxxxxx>

Marvell, please review patches from external contributors promptly.

Review question sort of based on a Sashiko comment - this is part of
the rvu device driver, AFAIU, does anything prevent the AF from getting
removed (via sysfs for instance) while this code is using its priv?

> Changes in v2:
> - Keep using the local RVU AF pdev returned by pci_get_device() instead
>   of cgx->pdev, because cgx->pdev belongs to the CGX/RPM device.
> - Rebase on current net-next so netdev CI can apply the patch.
>  .../marvell/octeontx2/af/rvu_debugfs.c        | 31 +++++++++++++++----
>  1 file changed, 25 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/net/ethernet/marvell/octeontx2/af/rvu_debugfs.c b/drivers/net/ethernet/marvell/octeontx2/af/rvu_debugfs.c
> index fa461489acdd..04ba091773b6 100644
> --- a/drivers/net/ethernet/marvell/octeontx2/af/rvu_debugfs.c
> +++ b/drivers/net/ethernet/marvell/octeontx2/af/rvu_debugfs.c
> @@ -2838,9 +2838,16 @@ static int cgx_print_stats(struct seq_file *s, int lmac_id)
>  	int stat = 0, err = 0;
>  	u64 tx_stat, rx_stat;
>  	struct rvu *rvu;
> +	struct pci_dev *pdev = NULL;
> +
> +	pdev = pci_get_device(PCI_VENDOR_ID_CAVIUM,
> +			      PCI_DEVID_OCTEONTX2_RVU_AF, NULL);
> +	if (!pdev)
> +		return -ENODEV;
> +
> +	rvu = pci_get_drvdata(pdev);
> +	pci_dev_put(pdev);
>  
> -	rvu = pci_get_drvdata(pci_get_device(PCI_VENDOR_ID_CAVIUM,
> -					     PCI_DEVID_OCTEONTX2_RVU_AF, NULL));
>  	if (!rvu)
>  		return -ENODEV;
>  
> @@ -2958,8 +2965,13 @@ static int cgx_print_dmac_flt(struct seq_file *s, int lmac_id)
>  	u64 cfg, mac;
>  	int pf;
>  
> -	rvu = pci_get_drvdata(pci_get_device(PCI_VENDOR_ID_CAVIUM,
> -					     PCI_DEVID_OCTEONTX2_RVU_AF, NULL));
> +	pdev = pci_get_device(PCI_VENDOR_ID_CAVIUM,
> +			      PCI_DEVID_OCTEONTX2_RVU_AF, NULL);
> +	if (!pdev)
> +		return -ENODEV;
> +
> +	rvu = pci_get_drvdata(pdev);
> +	pci_dev_put(pdev);
>  	if (!rvu)
>  		return -ENODEV;
>  
> @@ -3014,9 +3026,16 @@ static int cgx_print_fwdata(struct seq_file *s, int lmac_id)
>  	struct phy_s *phy;
>  	struct rvu *rvu;
>  	int cgx_id, i;
> +	struct pci_dev *pdev = NULL;
> +
> +	pdev = pci_get_device(PCI_VENDOR_ID_CAVIUM,
> +			      PCI_DEVID_OCTEONTX2_RVU_AF, NULL);
> +	if (!pdev)
> +		return -ENODEV;
> +
> +	rvu = pci_get_drvdata(pdev);
> +	pci_dev_put(pdev);
>  
> -	rvu = pci_get_drvdata(pci_get_device(PCI_VENDOR_ID_CAVIUM,
> -					     PCI_DEVID_OCTEONTX2_RVU_AF, NULL));
>  	if (!rvu)
>  		return -ENODEV;
>