On 19/05/2021 04:36, Yang Yingliang wrote:
On 2021/5/18 23:34, John Garry wrote:
On 18/05/2021 14:09, Yang Yingliang wrote:
irq allocated with devm_request_irq should not be freed using
free_irq, because doing so causes a dangling pointer, and a
subsequent double free.
Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx>
---
drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
index 499c770d405c..684f762bcfb3 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
@@ -4811,9 +4811,9 @@ hisi_sas_v3_destroy_irqs(struct pci_dev *pdev,
struct hisi_hba *hisi_hba)
{
int i;
- free_irq(pci_irq_vector(pdev, 1), hisi_hba);
- free_irq(pci_irq_vector(pdev, 2), hisi_hba);
- free_irq(pci_irq_vector(pdev, 11), hisi_hba);
+ devm_free_irq(&pdev->dev, pci_irq_vector(pdev, 1), hisi_hba);
+ devm_free_irq(&pdev->dev, pci_irq_vector(pdev, 2), hisi_hba);
+ devm_free_irq(&pdev->dev, pci_irq_vector(pdev, 11), hisi_hba);
for (i = 0; i < hisi_hba->cq_nvecs; i++) {
struct hisi_sas_cq *cq = &hisi_hba->cq[i];
int nr = hisi_sas_intr_conv ? 16 : 16 + i;
Does the free_irq(pci_irq_vector(pdev, nr, cq)) call also need to
change (not shown)?
Yes, I missed that, it should be changed too.
So I think that we need this addition:
devm_free_irq(&pdev->dev, pci_irq_vector(pdev, nr), cq);
Having said that, why have these at all if we use devm_request_irq()?
devm_irq_release() calls free_irq().
I keep the original logic here, only avoid double free.
Kasan doesn't complain. Anyway, I think we can't rely on device-managed
method (for calling free_irq()) as it conflicts with pci free vectors
call. I thought that someone was developed a device-managed version of
that (pci_alloc_irq_vectors()).
Anyway, please proceed with your change, but with the suggested addition.
Thanks
