[PATCH 1/1] iommu: Fix potential memory leak in iopf_queue_remove_device()

[PATCH 1/1] iommu: Fix potential memory leak in iopf_queue_remove_device()

[Lu Baolu]

The iopf_queue_remove_device() helper removes a device from the per-iommu
iopf queue when PRI is disabled on the device. It responds to all
outstanding iopf's with an IOMMU_PAGE_RESP_INVALID code and detaches the
device from the queue.

However, it fails to release the group structure that represents a group
of iopf's awaiting for a response after responding to the hardware. This
can cause a memory leak if iopf_queue_remove_device() is called with
pending iopf's.

Fix it by calling iopf_free_group() after the iopf group is responded.

Fixes: 199112327135 ("iommu: Track iopf group instead of last fault")
Cc: stable@vger.kernel.org
Suggested-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/iommu/io-pgfault.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c
index 4674e618797c..8b5926c1452e 100644
--- a/drivers/iommu/io-pgfault.c
+++ b/drivers/iommu/io-pgfault.c
@@ -478,6 +478,7 @@ void iopf_queue_remove_device(struct iopf_queue *queue, struct device *dev)
 
 		ops->page_response(dev, iopf, &resp);
 		list_del_init(&group->pending_node);
+		iopf_free_group(group);
 	}
 	mutex_unlock(&fault_param->lock);
 
-- 
2.43.0

RE: [PATCH 1/1] iommu: Fix potential memory leak in iopf_queue_remove_device()

[Tian, Kevin]

> From: Lu Baolu <baolu.lu@linux.intel.com>
> Sent: Friday, January 17, 2025 1:58 PM
> 
> The iopf_queue_remove_device() helper removes a device from the per-
> iommu
> iopf queue when PRI is disabled on the device. It responds to all
> outstanding iopf's with an IOMMU_PAGE_RESP_INVALID code and detaches
> the
> device from the queue.
> 
> However, it fails to release the group structure that represents a group
> of iopf's awaiting for a response after responding to the hardware. This
> can cause a memory leak if iopf_queue_remove_device() is called with
> pending iopf's.
> 
> Fix it by calling iopf_free_group() after the iopf group is responded.
> 
> Fixes: 199112327135 ("iommu: Track iopf group instead of last fault")
> Cc: stable@vger.kernel.org
> Suggested-by: Kevin Tian <kevin.tian@intel.com>
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>

Reviewed-by: Kevin Tian <kevin.tian@intel.com>

Re: [PATCH 1/1] iommu: Fix potential memory leak in iopf_queue_remove_device()

[Jason Gunthorpe]

On Fri, Jan 17, 2025 at 01:58:00PM +0800, Lu Baolu wrote:
> The iopf_queue_remove_device() helper removes a device from the per-iommu
> iopf queue when PRI is disabled on the device. It responds to all
> outstanding iopf's with an IOMMU_PAGE_RESP_INVALID code and detaches the
> device from the queue.
> 
> However, it fails to release the group structure that represents a group
> of iopf's awaiting for a response after responding to the hardware. This
> can cause a memory leak if iopf_queue_remove_device() is called with
> pending iopf's.
> 
> Fix it by calling iopf_free_group() after the iopf group is responded.
> 
> Fixes: 199112327135 ("iommu: Track iopf group instead of last fault")
> Cc: stable@vger.kernel.org
> Suggested-by: Kevin Tian <kevin.tian@intel.com>
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> ---
>  drivers/iommu/io-pgfault.c | 1 +
>  1 file changed, 1 insertion(+)

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Jason

Re: [PATCH 1/1] iommu: Fix potential memory leak in iopf_queue_remove_device()

[Joerg Roedel]

On Fri, Jan 17, 2025 at 01:58:00PM +0800, Lu Baolu wrote:
> The iopf_queue_remove_device() helper removes a device from the per-iommu
> iopf queue when PRI is disabled on the device. It responds to all
> outstanding iopf's with an IOMMU_PAGE_RESP_INVALID code and detaches the
> device from the queue.
> 
> However, it fails to release the group structure that represents a group
> of iopf's awaiting for a response after responding to the hardware. This
> can cause a memory leak if iopf_queue_remove_device() is called with
> pending iopf's.
> 
> Fix it by calling iopf_free_group() after the iopf group is responded.
> 
> Fixes: 199112327135 ("iommu: Track iopf group instead of last fault")
> Cc: stable@vger.kernel.org
> Suggested-by: Kevin Tian <kevin.tian@intel.com>
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>

Applied for -rc3, thanks.