[PATCH v2] misc: microchip: pci1xxxx: fix IRQ vector leak in gp_aux_bus_probe()

[Guangshuo Li]

gp_aux_bus_probe() allocates IRQ vectors with pci_alloc_irq_vectors()
before initializing and adding the second auxiliary device.

When pci_irq_vector(), auxiliary_device_init() or auxiliary_device_add()
for the second auxiliary device fails, the function unwinds the auxiliary
devices and ida allocations, but leaves the allocated IRQ vectors behind.

The issue was identified by a static analysis tool I developed and
confirmed by manual review. Add a dedicated error path to call
pci_free_irq_vectors() after IRQ vectors have been allocated
successfully.

Fixes: 393fc2f5948f ("misc: microchip: pci1xxxx: load auxiliary bus driver for the PIO function in the multi-function endpoint of pci1xxxx device.")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Guangshuo Li <lgs201920130244@xxxxxxxxx>
---
v2:
  - note that the issue was identified by my static analysis tool
  - and confirmed by manual review

 drivers/misc/mchp_pci1xxxx/mchp_pci1xxxx_gp.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/misc/mchp_pci1xxxx/mchp_pci1xxxx_gp.c b/drivers/misc/mchp_pci1xxxx/mchp_pci1xxxx_gp.c
index 34c9be437432..5e1f99a35100 100644
--- a/drivers/misc/mchp_pci1xxxx/mchp_pci1xxxx_gp.c
+++ b/drivers/misc/mchp_pci1xxxx/mchp_pci1xxxx_gp.c
@@ -93,14 +93,14 @@ static int gp_aux_bus_probe(struct pci_dev *pdev, const struct pci_device_id *id
 
 	retval = pci_irq_vector(pdev, 0);
 	if (retval < 0)
-		goto err_aux_dev_init_1;
+		goto err_irq_vectors;
 
 	pdev->irq = retval;
 	aux_bus->aux_device_wrapper[1]->gp_aux_data.irq_num = pdev->irq;
 
 	retval = auxiliary_device_init(&aux_bus->aux_device_wrapper[1]->aux_dev);
 	if (retval < 0)
-		goto err_aux_dev_init_1;
+		goto err_irq_vectors;
 
 	retval = auxiliary_device_add(&aux_bus->aux_device_wrapper[1]->aux_dev);
 	if (retval)
@@ -113,6 +113,9 @@ static int gp_aux_bus_probe(struct pci_dev *pdev, const struct pci_device_id *id
 
 err_aux_dev_add_1:
 	auxiliary_device_uninit(&aux_bus->aux_device_wrapper[1]->aux_dev);
+
+err_irq_vectors:
+	pci_free_irq_vectors(pdev);
 	goto err_aux_dev_add_0;
 
 err_aux_dev_init_1:
-- 
2.43.0