6.12-stable review patch. If anyone has any objections, please let me know.
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From: Kees Bakker kees@ijzerbout.nl
[ Upstream commit 60f030f7418d3f1d94f2fb207fe3080e1844630b ]
There is a WARN_ON_ONCE to catch an unlikely situation when domain_remove_dev_pasid can't find the `pasid`. In case it nevertheless happens we must avoid using a NULL pointer.
Signed-off-by: Kees Bakker kees@ijzerbout.nl Link: https://lore.kernel.org/r/20241218201048.E544818E57E@bout3.ijzerbout.nl Signed-off-by: Lu Baolu baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel jroedel@suse.de Signed-off-by: Amelia Crate acrate@waldn.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/iommu/intel/iommu.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
--- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -4328,13 +4328,14 @@ static void intel_iommu_remove_dev_pasid break; } } - WARN_ON_ONCE(!dev_pasid); spin_unlock_irqrestore(&dmar_domain->lock, flags);
cache_tag_unassign_domain(dmar_domain, dev, pasid); domain_detach_iommu(dmar_domain, iommu); - intel_iommu_debugfs_remove_dev_pasid(dev_pasid); - kfree(dev_pasid); + if (!WARN_ON_ONCE(!dev_pasid)) { + intel_iommu_debugfs_remove_dev_pasid(dev_pasid); + kfree(dev_pasid); + } intel_pasid_tear_down_entry(iommu, dev, pasid, false); intel_drain_pasid_prq(dev, pasid); }