In the Linux kernel, the following vulnerability has been resolved:
s390/vfio-ap: always filter entire AP matrix The vfio_ap_mdev_filter_matrix
function is called whenever a new adapter or domain is assigned to the
mdev. The purpose of the function is to update the guest’s AP configuration
by filtering the matrix of adapters and domains assigned to the mdev. When
an adapter or domain is assigned, only the APQNs associated with the APID
of the new adapter or APQI of the new domain are inspected. If an APQN does
not reference a queue device bound to the vfio_ap device driver, then it’s
APID will be filtered from the mdev’s matrix when updating the guest’s AP
configuration. Inspecting only the APID of the new adapter or APQI of the
new domain will result in passing AP queues through to a guest that are not
bound to the vfio_ap device driver under certain circumstances. Consider
the following: guest’s AP configuration (all also assigned to the mdev’s
matrix): 14.0004 14.0005 14.0006 16.0004 16.0005 16.0006 unassign domain 4
unbind queue 16.0005 assign domain 4 When domain 4 is re-assigned, since
only domain 4 will be inspected, the APQNs that will be examined will be:
14.0004 16.0004 Since both of those APQNs reference queue devices that are
bound to the vfio_ap device driver, nothing will get filtered from the
mdev’s matrix when updating the guest’s AP configuration. Consequently,
queue 16.0005 will get passed through despite not being bound to the
driver. This violates the linux device model requirement that a guest shall
only be given access to devices bound to the device driver facilitating
their pass-through. To resolve this problem, every adapter and domain
assigned to the mdev will be inspected when filtering the mdev’s matrix.
Author | Note |
---|---|
rodrigo-zaiden | USN-6765-1 for linux-oem-6.5 wrongly stated that this CVE was fixed in version 6.5.0-1022.23. The mentioned notice was revoked and the state of the fix for linux-oem-6.5 was recovered to the previous state. |
OS | Version | Architecture | Package | Version | Filename |
---|---|---|---|---|---|
ubuntu | 18.04 | noarch | linux | < any | UNKNOWN |
ubuntu | 20.04 | noarch | linux | < any | UNKNOWN |
ubuntu | 22.04 | noarch | linux | < any | UNKNOWN |
ubuntu | 23.10 | noarch | linux | < 6.5.0-41.41 | UNKNOWN |
ubuntu | 24.04 | noarch | linux | < any | UNKNOWN |
ubuntu | 14.04 | noarch | linux | < any | UNKNOWN |
ubuntu | 16.04 | noarch | linux | < any | UNKNOWN |
ubuntu | 18.04 | noarch | linux-aws | < any | UNKNOWN |
ubuntu | 20.04 | noarch | linux-aws | < any | UNKNOWN |
ubuntu | 22.04 | noarch | linux-aws | < any | UNKNOWN |
git.kernel.org/linus/850fb7fa8c684a4c6bf0e4b6978f4ddcc5d43d11 (6.8-rc1)
git.kernel.org/stable/c/850fb7fa8c684a4c6bf0e4b6978f4ddcc5d43d11
git.kernel.org/stable/c/c69d821197611678533fb3eb784fc823b921349a
git.kernel.org/stable/c/cdd134d56138302976685e6c7bc4755450b3880e
git.kernel.org/stable/c/d6b8d034b576f406af920a7bee81606c027b24c6
launchpad.net/bugs/cve/CVE-2024-26620
nvd.nist.gov/vuln/detail/CVE-2024-26620
security-tracker.debian.org/tracker/CVE-2024-26620
ubuntu.com/security/notices/USN-6818-1
ubuntu.com/security/notices/USN-6818-2
ubuntu.com/security/notices/USN-6818-3
ubuntu.com/security/notices/USN-6818-4
ubuntu.com/security/notices/USN-6819-1
ubuntu.com/security/notices/USN-6819-2
ubuntu.com/security/notices/USN-6819-3
ubuntu.com/security/notices/USN-6819-4
www.cve.org/CVERecord?id=CVE-2024-26620