[PATCH v1 3/4] iommu/vsi: Fix fwnode lookup lifetime handling
From: weimin xiong <hidden>
Date: 2026-07-14 06:10:30
Also in:
linux-arm-msm, linux-iommu, lkml
Subsystem:
iommu subsystem, the rest, verisilicon iommu driver · Maintainers:
Joerg Roedel, Will Deacon, Linus Torvalds, Benjamin Gaignard
bus_find_device_by_fwnode() returns a device with its reference count incremented. vsi_iommu_get_from_dev() drops that reference before reading the driver data, which leaves the returned pointer derived from a device after its reference has been released. Read the driver data before put_device(). Also make vsi_iommu_probe_device() fail with -ENODEV when the IOMMU cannot be found instead of dereferencing a NULL pointer. Signed-off-by: weimin xiong <redacted> --- drivers/iommu/vsi-iommu.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/iommu/vsi-iommu.c b/drivers/iommu/vsi-iommu.c
index 42c424496..d19db561e 100644
--- a/drivers/iommu/vsi-iommu.c
+++ b/drivers/iommu/vsi-iommu.c@@ -220,10 +220,15 @@ static struct vsi_iommu *vsi_iommu_get_from_dev(struct device *dev) struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev); struct device *iommu_dev = bus_find_device_by_fwnode(&platform_bus_type, fwspec->iommu_fwnode); + struct vsi_iommu *iommu; + + if (!iommu_dev) + return NULL; + iommu = dev_get_drvdata(iommu_dev); put_device(iommu_dev); - return iommu_dev ? dev_get_drvdata(iommu_dev) : NULL; + return iommu; } static struct iommu_domain *vsi_iommu_domain_alloc_paging(struct device *dev)
@@ -619,6 +624,9 @@ static struct iommu_device *vsi_iommu_probe_device(struct device *dev) struct vsi_iommu *iommu = vsi_iommu_get_from_dev(dev); struct device_link *link; + if (!iommu) + return ERR_PTR(-ENODEV); + link = device_link_add(dev, iommu->dev, DL_FLAG_STATELESS | DL_FLAG_PM_RUNTIME); if (!link)
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2.43.0