[PATCH] genirq/msi: Fix fwnode leak

[PATCH] genirq/msi: Fix fwnode leak

[Alex Williamson]

kmemleak is reporting pairs of leaked buffers when PCI devices are
unbound from their drivers.  One of these buffers contains the name of
the interrupt as generated for the msi_domain_template bundle in
msi_create_device_irq_domain().  This name is passed through
irq_domain_alloc_named_fwnode(), where an irqchip_rwid is allocated,
along with a separate allocation via kasprintf() for another copy of
the name.  These are the two leaked buffers.

Resolve this by adding the missing call to irq_domain_free_fwnode() in
msi_remove_device_irq_domain().

Fixes: 27a6dea3ebaa ("genirq/msi: Provide msi_create/free_device_irq_domain()")
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---
 kernel/irq/msi.c |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
index 955267bbc2be..66dc956505b8 100644
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -1015,6 +1015,7 @@ void msi_remove_device_irq_domain(struct device *dev, unsigned int domid)
 {
 	struct msi_domain_info *info;
 	struct irq_domain *domain;
+	struct fwnode_handle *fwnode;
 
 	msi_lock_descs(dev);
 
@@ -1025,7 +1026,9 @@ void msi_remove_device_irq_domain(struct device *dev, unsigned int domid)
 
 	dev->msi.data->__domains[domid].domain = NULL;
 	info = domain->host_data;
+	fwnode = domain->fwnode;
 	irq_domain_remove(domain);
+	irq_domain_free_fwnode(fwnode);
 	kfree(container_of(info, struct msi_domain_template, info));
 
 unlock:

Re: [PATCH] genirq/msi: Fix fwnode leak

[Marc Zyngier]

On Wed, 25 Jan 2023 23:13:48 +0000,
Alex Williamson <alex.williamson@redhat.com> wrote:
> 
> kmemleak is reporting pairs of leaked buffers when PCI devices are
> unbound from their drivers.  One of these buffers contains the name of
> the interrupt as generated for the msi_domain_template bundle in
> msi_create_device_irq_domain().  This name is passed through
> irq_domain_alloc_named_fwnode(), where an irqchip_rwid is allocated,
> along with a separate allocation via kasprintf() for another copy of
> the name.  These are the two leaked buffers.
> 
> Resolve this by adding the missing call to irq_domain_free_fwnode() in
> msi_remove_device_irq_domain().
> 
> Fixes: 27a6dea3ebaa ("genirq/msi: Provide msi_create/free_device_irq_domain()")
> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

Thomas has already queued this:

commit ac8f29aef2f1695956ff6773b33f975290437f29 (tip/irq/urgent)
Author: Jason Gunthorpe <jgg@ziepe.ca>
Date:   Tue Jan 17 15:16:17 2023 -0400

    genirq/msi: Free the fwnode created by msi_create_device_irq_domain()

which I assume will make it into Linus' tree shortly.

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.