From 68ec78beb4a3fb0877cbaaf49758c85410c05977 Mon Sep 17 00:00:00 2001 From: Kees Bakker Date: Thu, 30 Oct 2025 11:08:31 -0500 Subject: [PATCH] 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 Link: https://lore.kernel.org/r/20241218201048.E544818E57E@bout3.ijzerbout.nl Signed-off-by: Lu Baolu Signed-off-by: Joerg Roedel Signed-off-by: Amelia Crate Signed-off-by: Greg Kroah-Hartman --- 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); }