From f1cefc290c20c30c37b01d44b42ca5c9b6d32913 Mon Sep 17 00:00:00 2001 From: Kees Bakker kees@ijzerbout.nl Date: Tue, 7 Jan 2025 10:17:42 +0800 Subject: [PATCH 1/4] iommu/vt-d: Avoid use of NULL after WARN_ON_ONCE
[ 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 --- drivers/iommu/intel/iommu.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 667407974e23..c799cc67db34 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -4328,13 +4328,14 @@ static void intel_iommu_remove_dev_pasid(struct device *dev, ioasid_t 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); } -- 2.50.1