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

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

[Yuho Choi]

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@gmail.com>
---
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;
 
-- 
2.43.0