[ Sasha's backport helper bot ]
Hi,
The upstream commit SHA1 provided is correct: 229e6ee43d2a160a1592b83aad620d6027084aad
WARNING: Author mismatch between patch and upstream commit: Backport author: Robin Murphy robin.murphy@arm.com Commit author: Pratyush Brahma quic_pbrahma@quicinc.com
Status in newer kernel trees: 6.12.y | Present (different SHA1: 5018696b19bc) 6.6.y | Present (different SHA1: fe9d9839a755)
Note: The patch differs from the upstream commit: --- 1: 229e6ee43d2a1 ! 1: a937416dbd5d3 iommu/arm-smmu: Defer probe of clients after smmu device bound @@ Metadata ## Commit message ## iommu/arm-smmu: Defer probe of clients after smmu device bound
+ [ Upstream commit 229e6ee43d2a160a1592b83aad620d6027084aad ] + Null pointer dereference occurs due to a race between smmu driver probe and client driver probe, when of_dma_configure() for client is called after the iommu_device_register() for smmu driver @@ Commit message until the smmu device has bound to the arm smmu driver.
Fixes: 021bb8420d44 ("iommu/arm-smmu: Wire up generic configuration support") - Cc: stable@vger.kernel.org + Cc: stable@vger.kernel.org # 6.6 Co-developed-by: Prakash Gupta quic_guptap@quicinc.com Signed-off-by: Prakash Gupta quic_guptap@quicinc.com Signed-off-by: Pratyush Brahma quic_pbrahma@quicinc.com Link: https://lore.kernel.org/r/20241004090428.2035-1-quic_pbrahma@quicinc.com [will: Add comment] Signed-off-by: Will Deacon will@kernel.org + [rm: backport for context conflict prior to 6.8] + Signed-off-by: Robin Murphy robin.murphy@arm.com
## drivers/iommu/arm/arm-smmu/arm-smmu.c ## @@ drivers/iommu/arm/arm-smmu/arm-smmu.c: static struct iommu_device *arm_smmu_probe_device(struct device *dev) goto out_free; - } else { + } else if (fwspec && fwspec->ops == &arm_smmu_ops) { smmu = arm_smmu_get_by_fwnode(fwspec->iommu_fwnode); + + /* @@ drivers/iommu/arm/arm-smmu/arm-smmu.c: static struct iommu_device *arm_smmu_prob + if (!smmu) + return ERR_PTR(dev_err_probe(dev, -EPROBE_DEFER, + "smmu dev has not bound yet\n")); + } else { + return ERR_PTR(-ENODEV); } - - ret = -EINVAL; ---
Results of testing on various branches:
| Branch | Patch Apply | Build Test | |---------------------------|-------------|------------| | stable/linux-6.6.y | Success | Success |