[PATCH v2] uio: fix IRQ vector leak on probe failure and remove

[Guangshuo Li]

probe() allocates MSI/MSI-X vectors with pci_alloc_irq_vectors(), but
neither the error path nor remove() releases them with
pci_free_irq_vectors().

Unlike drivers using pcim_enable_device(), this driver uses
pci_enable_device(), so the IRQ vectors are not managed automatically
and must be freed explicitly.

Add pci_free_irq_vectors() to the probe error path after successful
vector allocation and to remove(). The issue was identified by a
static analysis tool I developed.

Fixes: 3397c3cd859a ("uio: Add SVA support for PCI devices via uio_pci_generic_sva.c")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Guangshuo Li <lgs201920130244@xxxxxxxxx>
---
v2:
  - Change have_irq_vectors from int to bool.
  - Set have_irq_vectors immediately after successful IRQ vector allocation.

 drivers/uio/uio_pci_generic_sva.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/uio/uio_pci_generic_sva.c b/drivers/uio/uio_pci_generic_sva.c
index 4a46acd994a8..e216436c9116 100644
--- a/drivers/uio/uio_pci_generic_sva.c
+++ b/drivers/uio/uio_pci_generic_sva.c
@@ -63,6 +63,7 @@ static int probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
 	struct uio_pci_sva_dev *udev;
 	int ret, i, irq = 0;
+	bool have_irq_vectors = false;
 
 	ret = pci_enable_device(pdev);
 	if (ret) {
@@ -78,6 +79,8 @@ static int probe(struct pci_dev *pdev, const struct pci_device_id *id)
 
 	ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSIX | PCI_IRQ_MSI);
 	if (ret > 0) {
+		have_irq_vectors = true;
+
 		irq = pci_irq_vector(pdev, 0);
 		if (irq < 0) {
 			dev_err(&pdev->dev, "Failed to get MSI vector\n");
@@ -139,6 +142,8 @@ static int probe(struct pci_dev *pdev, const struct pci_device_id *id)
 out_free:
 	kfree(udev);
 out_disable:
+	if (have_irq_vectors)
+		pci_free_irq_vectors(pdev);
 	pci_disable_device(pdev);
 
 	return ret;
@@ -148,6 +153,7 @@ static void remove(struct pci_dev *pdev)
 {
 	struct uio_pci_sva_dev *udev = pci_get_drvdata(pdev);
 
+	pci_free_irq_vectors(pdev);
 	pci_release_regions(pdev);
 	pci_disable_device(pdev);
 	kfree(udev);
-- 
2.43.0