Messages in this thread Patch in this message | | | From | Frank Wunderlich <> | Subject | [PATCH v2] iommu: Check if group is NULL before remove device | Date | Sat, 31 Jul 2021 09:47:37 +0200 |
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From: Frank Wunderlich <frank-w@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 <frank-w@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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