Re: [PATCH] PCI/MSI: Fix memory leak in pci_alloc_irq_vectors_affinity INTx path

From: Hans Zhang

Date: Mon Apr 20 2026 - 00:48:18 EST




On 4/20/26 12:09, neilfsun wrote:
In the INTx fallback path of pci_alloc_irq_vectors_affinity(),
affinity masks are created and never freed.

Signed-off-by: neilfsun <neilfsun@xxxxxxxxxxx>
Signed-off-by: Sun Feng <loyou85@xxxxxxxxx>
---
drivers/pci/msi/api.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/msi/api.c b/drivers/pci/msi/api.c
index c18559b6272c..c1377f74b8f3 100644
--- a/drivers/pci/msi/api.c
+++ b/drivers/pci/msi/api.c
@@ -280,14 +280,17 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs,
/* use INTx IRQ if allowed */
if (flags & PCI_IRQ_INTX) {
if (min_vecs == 1 && dev->irq) {
+ struct irq_affinity_desc *masks = NULL;
+
/*
* Invoke the affinity spreading logic to ensure that
* the device driver can adjust queue configuration
* for the single interrupt case.
*/
if (affd)
- irq_create_affinity_masks(1, affd);
+ masks = irq_create_affinity_masks(1, affd);

Hi,

Suggestion:

diff --git a/drivers/pci/msi/api.c b/drivers/pci/msi/api.c
index c18559b6272c..0ce34db2b2bf 100644
--- a/drivers/pci/msi/api.c
+++ b/drivers/pci/msi/api.c
@@ -286,7 +286,8 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs,
* for the single interrupt case.
*/
if (affd)
- irq_create_affinity_masks(1, affd);
+ struct irq_affinity_desc *masks __free(kfree) =
+ irq_create_affinity_masks(1, affd);
pci_intx(dev, 1);
return 1;
}


Best regards,
Hans

pci_intx(dev, 1);
+ kfree(masks);
return 1;
}
}