From: Frank Wunderlich frank-w@public-files.de
[ Upstream commit 5aa95d8834e07907e64937d792c12ffef7fb271f ]
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 Link: https://lore.kernel.org/r/20210731074737.4573-1-linux@fw-web.de Signed-off-by: Joerg Roedel jroedel@suse.de Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/iommu/iommu.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 9b8664d388af..bcf060b5cf85 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -879,6 +879,9 @@ 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. */