From: Frank Wunderlich <fran...@public-files.de>
If probe_device is failing, iommu_group is not initialized because
iommu_group_add_device is not reached, so freeing it will result
in NULL pointer access.
iommu_bus_init
->bus_iommu_probe
->probe_iommu_group in for each:/* return -22 in fail case */
->iommu_probe_device
->__iommu_probe_device /* return -22 here.*/
-> ops->probe_device /* return -22 here.*/
-> iommu_group_get_for_dev
-> ops->device_group
-> iommu_group_add_device //good case
->remove_iommu_group //in fail case, it will remove group
->iommu_release_device
->iommu_group_remove_device // here we don't have group
In my case ops->probe_device (mtk_iommu_probe_device from
mtk_iommu_v1.c) is due to failing fwspec->ops mismatch.
Fixes: d72e31c93746 ("iommu: IOMMU Groups")
Signed-off-by: Frank Wunderlich <fran...@public-files.de>
---
v2:
- commit-message with captial letters on beginning of sentenence
- added more information, many thanks to Yong Wu
---
drivers/iommu/iommu.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 5419c4b9f27a..63f0af10c403 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -924,6 +924,9 @@ void iommu_group_remove_device(struct device *dev)
struct iommu_group *group = dev->iommu_group;
struct group_device *tmp_device, *device = NULL;
+ if (!group)
+ return;
+
dev_info(dev, "Removing from iommu group %d\n", group->id);
/* Pre-notify listeners that a device is being removed. */
--
2.25.1
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