From 81e921fd321614c2ad8ac333b041aae1da7a1c6d Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Tue, 5 Mar 2024 20:21:18 +0800 Subject: iommu/vt-d: Fix NULL domain on device release In the kdump kernel, the IOMMU operates in deferred_attach mode. In this mode, info->domain may not yet be assigned by the time the release_device function is called. It leads to the following crash in the crash kernel: BUG: kernel NULL pointer dereference, address: 000000000000003c ... RIP: 0010:do_raw_spin_lock+0xa/0xa0 ... _raw_spin_lock_irqsave+0x1b/0x30 intel_iommu_release_device+0x96/0x170 iommu_deinit_device+0x39/0xf0 __iommu_group_remove_device+0xa0/0xd0 iommu_bus_notifier+0x55/0xb0 notifier_call_chain+0x5a/0xd0 blocking_notifier_call_chain+0x41/0x60 bus_notify+0x34/0x50 device_del+0x269/0x3d0 pci_remove_bus_device+0x77/0x100 p2sb_bar+0xae/0x1d0 ... i801_probe+0x423/0x740 Use the release_domain mechanism to fix it. The scalable mode context entry which is not part of release domain should be cleared in release_device(). Fixes: 586081d3f6b1 ("iommu/vt-d: Remove DEFER_DEVICE_DOMAIN_INFO") Reported-by: Eric Badger Closes: https://lore.kernel.org/r/20240113181713.1817855-1-ebadger@purestorage.com Signed-off-by: Lu Baolu Reviewed-by: Kevin Tian Link: https://lore.kernel.org/r/20240305013305.204605-3-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- drivers/iommu/intel/iommu.c | 31 ++++++------------------------- 1 file changed, 6 insertions(+), 25 deletions(-) (limited to 'drivers/iommu/intel/iommu.c') diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 60aa2dce32ef..eff7abcc420b 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -3818,30 +3818,6 @@ static void domain_context_clear(struct device_domain_info *info) &domain_context_clear_one_cb, info); } -static void dmar_remove_one_dev_info(struct device *dev) -{ - struct device_domain_info *info = dev_iommu_priv_get(dev); - struct dmar_domain *domain = info->domain; - struct intel_iommu *iommu = info->iommu; - unsigned long flags; - - if (!dev_is_real_dma_subdevice(info->dev)) { - if (dev_is_pci(info->dev) && sm_supported(iommu)) - intel_pasid_tear_down_entry(iommu, info->dev, - IOMMU_NO_PASID, false); - - iommu_disable_pci_caps(info); - domain_context_clear(info); - } - - spin_lock_irqsave(&domain->lock, flags); - list_del(&info->link); - spin_unlock_irqrestore(&domain->lock, flags); - - domain_detach_iommu(domain, iommu); - info->domain = NULL; -} - /* * Clear the page table pointer in context or pasid table entries so that * all DMA requests without PASID from the device are blocked. If the page @@ -4367,7 +4343,11 @@ static void intel_iommu_release_device(struct device *dev) mutex_lock(&iommu->iopf_lock); device_rbtree_remove(info); mutex_unlock(&iommu->iopf_lock); - dmar_remove_one_dev_info(dev); + + if (sm_supported(iommu) && !dev_is_real_dma_subdevice(dev) && + !context_copied(iommu, info->bus, info->devfn)) + intel_pasid_teardown_sm_context(dev); + intel_pasid_free_table(dev); intel_iommu_debugfs_remove_dev(info); kfree(info); @@ -4826,6 +4806,7 @@ static const struct iommu_dirty_ops intel_dirty_ops = { const struct iommu_ops intel_iommu_ops = { .blocked_domain = &blocking_domain, + .release_domain = &blocking_domain, .capable = intel_iommu_capable, .hw_info = intel_iommu_hw_info, .domain_alloc = intel_iommu_domain_alloc, -- cgit v1.2.3