[PATCH 1/1] [media] ddbridge: Do not free_irq() if request_irq() failed

From: Takeshi Yoshimura
Date: Wed May 27 2015 - 10:30:33 EST


From: Takeshi Yoshimura <yos@xxxxxxxxxxxxxxxxxxxx>

My static checker detected that free_irq() is called even after
request_irq() failed in ddb_probe(). In this case, the kernel may try to
free dev->pdev->irq although the IRQ is not assigned. This event rarely
occurs, but always introduces a warning if it happens.

"goto fail1" always results in disabling enabled MSI and releasing a
requested IRQ. It seems like the former handling is necessary. So I added
a conditional branch before the free_irq() (stat == 0 means request_irq()
succeeds).

Signed-off-by: Takeshi Yoshimura <yos@xxxxxxxxxxxxxxxxxxxx>
---
drivers/media/pci/ddbridge/ddbridge-core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/media/pci/ddbridge/ddbridge-core.c b/drivers/media/pci/ddbridge/ddbridge-core.c
index 9e3492e..0ac2dd3 100644
--- a/drivers/media/pci/ddbridge/ddbridge-core.c
+++ b/drivers/media/pci/ddbridge/ddbridge-core.c
@@ -1630,7 +1630,8 @@ fail1:
printk(KERN_ERR "fail1\n");
if (dev->msi)
pci_disable_msi(dev->pdev);
- free_irq(dev->pdev->irq, dev);
+ if (stat == 0)
+ free_irq(dev->pdev->irq, dev);
fail:
printk(KERN_ERR "fail\n");
ddb_unmap(dev);
--
2.1.0

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