CVE-2026-52953

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: 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.

Weakness

The product reads data past the end, or before the beginning, of the intended buffer.

Affected Software

Potential Mitigations

• Assume all input is malicious. Use an “accept known good” input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
• When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, “boat” may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as “red” or “blue.”
• Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code’s environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
• To reduce the likelihood of introducing an out-of-bounds read, ensure that you validate and ensure correct calculations for any length argument, buffer size calculation, or offset. Be especially careful of relying on a sentinel (i.e. special character such as NUL) in untrusted inputs.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/540.html

References

• https://git.kernel.org/stable/c/1e659db468476733d217c1314c1e0d9244356d6c
• https://git.kernel.org/stable/c/88397fad7914ee74a7880fa5ce01f9eb6bfe0743
• https://git.kernel.org/stable/c/a6dea58d8625c06b9654c0555f101742481335c3