Bug 2492320 (CVE-2026-52953)

Summary: CVE-2026-52953 kernel: iommu/vt-d: Fix oops due to out of scope access
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in the Linux kernel's input/output memory management unit (IOMMU) virtualized directed I/O (VT-d) subsystem. This vulnerability occurs due to an out-of-scope memory access when a QEMU process is terminated. An attacker could potentially trigger a general protection fault, leading to a kernel oops and causing a denial of service (DoS) on the affected system.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description OSIDB Bzimport 2026-06-24 18:05:31 UTC
In the Linux kernel, the following vulnerability has been resolved:

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.