[PATCH rc 2/2] iommu/tegra241-cmdqv: Fix UAF due to re-entry of tegra241_cmdqv_remove()

[Nicolin Chen]

When falling back to standard SMMU CMDQ, impl_ops must be set to NULL, so
tegra241_cmdqv_remove() will not be re-entered by arm_smmu_impl_remove(),
which will trigger a UAF.

Fixes: 483e0bd8883a ("iommu/tegra241-cmdqv: Do not allocate vcmdq until dma_set_mask_and_coherent")
Cc: stable at vger.kernel.org
Signed-off-by: Nicolin Chen <nicolinc at nvidia.com>
---
 drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c b/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c
index ce7be8eeb43c..8249ef087af3 100644
--- a/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c
+++ b/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c
@@ -803,6 +803,7 @@ static int tegra241_cmdqv_init_structures(struct arm_smmu_device *smmu)
 	dev_info(smmu->impl_dev, "Falling back to standard SMMU CMDQ\n");
 	smmu->options &= ~ARM_SMMU_OPT_TEGRA241_CMDQV;
 	tegra241_cmdqv_remove(smmu);
+	smmu->impl_ops = NULL;
 	return 0;
 }
 
-- 
2.43.0