Linux vulnerability

What happened

In the Linux kernel, the following vulnerability has been resolved: iommufd: Fix UAF in selftest IOPF reporting IOMMUFD selftest TRIGGER_IOPF borrows an attach handle from group->pasid_array without synchronizing against PASID detach, then a concurrent iommu_report_device_fault() can dereference that borrowed handle's domain pointer after the detach erases the handle and frees the backing struct iommufd_attach_handle. TRIGGER_IOPF then dereferences the freed handle, causing a UAF. Fix by adding a iopf_rwsem in mock_dev to follow the expected design of a real driver. Hold its read side across the whole iommu_report_device_fault() call, and its write side around every path that attaches, detaches, or replaces a device domain. This can block new reports and drains in-flight reports before an old attach handle or the IOPF fault parameter can be removed. Also take the write side while registering a mock device, since it can invoke the mock driver's default-domain attach callback.

Affected versions

Linux: ddee19971081b42615d62f4fdada21274708ed4d through before cab2895729516799384d48560e6fca105fb3f927 (git); ddee19971081b42615d62f4fdada21274708ed4d through before e27e90bde68b2ab92e63ed19caad1ef57188bea0 (git); ddee19971081b42615d62f4fdada21274708ed4d through before 8c07df7cdfcf52f1ff276c588612aabc6c6b8399 (git); 6.11 Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

• Apply vendor-provided updates or mitigations.
• Review affected product exposure and access logs.