From 60f030f7418d3f1d94f2fb207fe3080e1844630b Mon Sep 17 00:00:00 2001 From: Kees Bakker Date: Tue, 7 Jan 2025 10:17:42 +0800 Subject: [PATCH] iommu/vt-d: Avoid use of NULL after WARN_ON_ONCE 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 --- 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 79e0da9eb626..8f75c11a3ec4 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -4090,13 +4090,14 @@ void domain_remove_dev_pasid(struct iommu_domain *domain, 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); + } } static void intel_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid, -- 2.50.1