[PATCH v7 1/1] media: saa7164: add ioremap return checks and cleanups

[Wang Jun]

Add checks for ioremap return values in saa7164_dev_setup(). If
ioremap for BAR0 or BAR2 fails, release the already allocated PCI
memory regions, remove the device from the global list, decrement
the device count, and return -ENODEV.

This prevents potential null pointer dereferences and ensures proper
cleanup on memory mapping failures.

Fixes: 443c1228d505 ("V4L/DVB (12923): SAA7164: Add support for the NXP SAA7164 silicon")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Wang Jun <1742789905@xxxxxx>
---
 drivers/media/pci/saa7164/saa7164-core.c | 47 ++++++++++++++++++------
 1 file changed, 35 insertions(+), 12 deletions(-)

diff --git a/drivers/media/pci/saa7164/saa7164-core.c b/drivers/media/pci/saa7164/saa7164-core.c
index 74406d5ea0a5..e8037ac1db73 100644
--- a/drivers/media/pci/saa7164/saa7164-core.c
+++ b/drivers/media/pci/saa7164/saa7164-core.c
@@ -888,6 +888,15 @@ static int get_resources(struct saa7164_dev *dev)
 	return -EBUSY;
 }
 
+static void release_resources(struct saa7164_dev *dev)
+{
+	release_mem_region(pci_resource_start(dev->pci, 0),
+			   pci_resource_len(dev->pci, 0));
+
+	release_mem_region(pci_resource_start(dev->pci, 2),
+			   pci_resource_len(dev->pci, 2));
+}
+
 static int saa7164_port_init(struct saa7164_dev *dev, int portnr)
 {
 	struct saa7164_port *port = NULL;
@@ -947,9 +956,9 @@ static int saa7164_dev_setup(struct saa7164_dev *dev)
 
 	snprintf(dev->name, sizeof(dev->name), "saa7164[%d]", dev->nr);
 
-	mutex_lock(&devlist);
-	list_add_tail(&dev->devlist, &saa7164_devlist);
-	mutex_unlock(&devlist);
+	scoped_guard(mutex, &devlist) {
+		list_add_tail(&dev->devlist, &saa7164_devlist);
+	}
 
 	/* board config */
 	dev->board = UNSET;
@@ -996,11 +1005,17 @@ static int saa7164_dev_setup(struct saa7164_dev *dev)
 	}
 
 	/* PCI/e allocations */
-	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, "Failed to remap MMIO BAR 0\n");
+		goto err_ioremap_bar0;
+	}
 
-	dev->lmmio2 = ioremap(pci_resource_start(dev->pci, 2),
-			     pci_resource_len(dev->pci, 2));
+	dev->lmmio2 = pci_ioremap_bar(dev->pci, 2);
+	if (!dev->lmmio2) {
+		dev_err(&dev->pci->dev, "Failed to remap MMIO BAR 2\n");
+		goto err_ioremap_bar2;
+	}
 
 	dev->bmmio = (u8 __iomem *)dev->lmmio;
 	dev->bmmio2 = (u8 __iomem *)dev->lmmio2;
@@ -1019,17 +1034,25 @@ static int saa7164_dev_setup(struct saa7164_dev *dev)
 	saa7164_pci_quirks(dev);
 
 	return 0;
+
+err_ioremap_bar2:
+	iounmap(dev->lmmio);
+err_ioremap_bar0:
+	release_resources(dev);
+
+	scoped_guard(mutex, &devlist) {
+		list_del(&dev->devlist);
+	}
+	saa7164_devcount--;
+
+	return	-ENODEV;
 }
 
 static void saa7164_dev_unregister(struct saa7164_dev *dev)
 {
 	dprintk(1, "%s()\n", __func__);
 
-	release_mem_region(pci_resource_start(dev->pci, 0),
-		pci_resource_len(dev->pci, 0));
-
-	release_mem_region(pci_resource_start(dev->pci, 2),
-		pci_resource_len(dev->pci, 2));
+	release_resources(dev);
 
 	if (!atomic_dec_and_test(&dev->refcount))
 		return;
-- 
2.43.0