FAILED: patch "[PATCH] iommu/vt-d: Fix oops due to out of scope access" failed to apply to 6.6-stable tree

The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x a6dea58d8625c06b9654c0555f101742481335c3
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026052008-rewire-diffused-adb7@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From a6dea58d8625c06b9654c0555f101742481335c3 Mon Sep 17 00:00:00 2001
From: Zhenzhong Duan <[email protected]>
Date: Sat, 9 May 2026 10:43:45 +0800
Subject: [PATCH] iommu/vt-d: Fix oops due to out of scope access

Below oops triggers when kill QEMU process:

  Oops: general protection fault, probably for non-canonical address 0x7fffffff844eaaa7: 0000 [#1] SMP NOPTI
  Call Trace:
   <TASK>
   do_raw_spin_lock+0xaa/0xc0
   _raw_spin_lock_irqsave+0x21/0x40
   domain_remove_dev_pasid+0x52/0x160
   intel_nested_set_dev_pasid+0x1b9/0x1e0
   __iommu_set_group_pasid+0x56/0x120
   pci_dev_reset_iommu_done+0xe3/0x180
   pcie_flr+0x65/0x160
   __pci_reset_function_locked+0x5b/0x120
   vfio_pci_core_close_device+0x63/0xe0 [vfio_pci_core]
   vfio_df_close+0x4f/0xa0
   vfio_df_unbind_iommufd+0x2d/0x60
   vfio_device_fops_release+0x3e/0x40
   __fput+0xe5/0x2c0
   task_work_run+0x58/0xa0
   do_exit+0x2c8/0x600
   do_group_exit+0x2f/0xa0
   get_signal+0x863/0x8c0
   arch_do_signal_or_restart+0x24/0x100
   exit_to_user_mode_loop+0x87/0x380
   do_syscall_64+0x2ff/0x11e0
   entry_SYSCALL_64_after_hwframe+0x76/0x7e

The global static blocked domain is a dummy domain without corresponding dmar_domain structure, accessing beyond iommu_domain structure triggers oops easily. Fix it by return early in domain_remove_dev_pasid() like identity domain.

index 2a6b6813a78d..a4b123c33022 100644
@@ -3530,8 +3530,8 @@ void domain_remove_dev_pasid(struct iommu_domain *domain,
 	if (!domain)
 		return;
 
-	/* Identity domain has no meta data for pasid. */
-	if (domain->type == IOMMU_DOMAIN_IDENTITY)
+	/* Identity domain and blocked domain have no meta data for pasid. */
+	if (domain->type == IOMMU_DOMAIN_IDENTITY || domain->type == IOMMU_DOMAIN_BLOCKED)
 		return;
 
 	dmar_domain = to_dmar_domain(domain);