Add a check for the return value of pci_ioremap_bar()
in cx23885_dev_setup().
If ioremap for BAR0 fails, release the already allocated
PCI memory region,
decrement the device count, and return -ENODEV.

This prevents a potential null pointer dereference and
ensures proper cleanup
on memory mapping failure.

Fixes: d19770e5178a ("V4L/DVB (6150): Add CX23885/CX23887 PCIe bridge driver")
Cc: stable@vger.kernel.org
Signed-off-by: Wang Jun <1742789905@qq.com>
---
 drivers/media/pci/cx23885/cx23885-core.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/media/pci/cx23885/cx23885-core.c b/drivers/media/pci/cx23885/cx23885-core.c
index 0892a5fd137d..98878b6a448a 100644
--- a/drivers/media/pci/cx23885/cx23885-core.c
+++ b/drivers/media/pci/cx23885/cx23885-core.c
@@ -990,8 +990,12 @@ static int cx23885_dev_setup(struct cx23885_dev *dev)
 	}
 
 	/* PCIe stuff */
-	dev->lmmio = ioremap(pci_resource_start(dev->pci, 0),
-			     pci_resource_len(dev->pci, 0));
+	dev->lmmio = pci_ioremap_bar(dev->pci, 0);
+	if (!dev->lmmio) {
+		dev_err(&dev->pci->dev, "CORE %s: can't ioremap MMIO memory\n",
+			dev->name);
+		goto err_release_region;
+	}
 
 	dev->bmmio = (u8 __iomem *)dev->lmmio;
 
@@ -1096,6 +1100,12 @@ static int cx23885_dev_setup(struct cx23885_dev *dev)
 	}
 
 	return 0;
+
+err_release_region:
+	release_mem_region(pci_resource_start(dev->pci, 0),
+			   pci_resource_len(dev->pci, 0));
+	cx23885_devcount--;
+	return -ENODEV;
 }
 
 static void cx23885_dev_unregister(struct cx23885_dev *dev)
-- 
2.43.0