CVE-2026-80894

iommufd: Fix wrong hwpt passed to iommufd_auto_response_faults on replace

Published Sep 4, 2026 CVSS n/a EPSS < 1% KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:

iommufd: Fix wrong hwpt passed to iommufd_auto_response_faults on replace

iommufd_hwpt_replace_device() calls:

iommufd_auto_response_faults(hwpt, old_handle);

passing the *new* hwpt together with the handle of
the device's *old* domain. This should be a parameter mismatch:

1. Semantically, iommufd_auto_response_faults(x, handle) scans
x->fault's deliver list and response xarray for groups matching
"handle". A group is queued under the hwpt that was attached at
fault-delivery time. old_handle is fetched *before* the domain switch,
so its group lives on old->fault, not on the new hwpt->fault.

2. Historically, the first argument was "old". The routine was
introduced by commit b7d8833677ba ("iommufd: Fault-capable hwpt
attach/detach/replace") as __fault_domain_replace_dev() in
fault.c, correctly calling iommufd_auto_response_faults(old, curr).
Commit fb21b1568ada ("iommufd: Make attach_handle generic than
fault specific") moved this into iommufd_hwpt_replace_device() in
device.c and swapped it to "hwpt". This should be a refactor regression,
not an intentional change.

Fix this by passing "old" instead.

Remediation

No solution or workaround provided in the CVE record

Tracking

Sign in to view the affected projects.

Advisories

Source ID Title
Debian DLA Debian DLA DLA-4788-1 linux-6.12 security update
Ubuntu USN Ubuntu USN USN-9019-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-9020-1 Linux kernel vulnerabilities
History
Type Values Removed Values Added
Weaknesses CWE-398
Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: iommufd: Fix wrong hwpt passed to iommufd_auto_response_faults on replace iommufd_hwpt_replace_device() calls: iommufd_auto_response_faults(hwpt, old_handle); passing the *new* hwpt together with the handle of the device's *old* domain. This should be a parameter mismatch: 1. Semantically, iommufd_auto_response_faults(x, handle) scans x->fault's deliver list and response xarray for groups matching "handle". A group is queued under the hwpt that was attached at fault-delivery time. old_handle is fetched *before* the domain switch, so its group lives on old->fault, not on the new hwpt->fault. 2. Historically, the first argument was "old". The routine was introduced by commit b7d8833677ba ("iommufd: Fault-capable hwpt attach/detach/replace") as __fault_domain_replace_dev() in fault.c, correctly calling iommufd_auto_response_faults(old, curr). Commit fb21b1568ada ("iommufd: Make attach_handle generic than fault specific") moved this into iommufd_hwpt_replace_device() in device.c and swapped it to "hwpt". This should be a refactor regression, not an intentional change. Fix this by passing "old" instead.
Title iommufd: Fix wrong hwpt passed to iommufd_auto_response_faults on replace
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
Sep 4, 2026, 5:11 PM
Reserved
Aug 26, 2026, 2:34 PM
Status
Received
Published
Sep 4, 2026, 6:17 PM
Modified
Sep 4, 2026, 6:17 PM