In the Linux kernel, the following vulnerability has been resolved:

liveupdate: validate session type before performing operation

The sessions ioctls are not applicable to all session types. PRESERVE_FD
is only applicable to outgoing sessions. RETRIEVE_FD and FINISH are only
valid for incoming session. Calling a incoming ioctl on an outgoing
session is invalid and can cause file handlers to run into unexpected
errors.

For example, a user can create a (outgoing) session, preserve a memfd,
and then immediately do a retrieve without doing a kexec in between.
This would result in memfd's retrieve handler to run. The handlers
expects to be called from a post-kexec context, and will try to do a
kho_restore_vmalloc() or kho_restore_folio() to try and restore memory.

KHO catches this (thanks to KHO_PAGE_MAGIC) and returns an error, but
since this is considered an internal error and KHO throws out a bunch of
WARN()s.

Associate a type with each ioctl op and validate the type in
luo_session_ioctl() before dispatching the ioctl handler to make sure
the op is being called for the right session type.
Advisories
Source ID Title
Ubuntu USN Ubuntu USN USN-8887-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8888-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-8889-1 Linux kernel (OEM) vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Tue, 18 Aug 2026 04:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-284

Tue, 18 Aug 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-1287
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate


Sat, 15 Aug 2026 08:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-284

Sat, 15 Aug 2026 07:45:00 +0000

Type Values Removed Values Added
First Time appeared Linux kernel
Vendors & Products Linux kernel

Sat, 15 Aug 2026 06:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: liveupdate: validate session type before performing operation The sessions ioctls are not applicable to all session types. PRESERVE_FD is only applicable to outgoing sessions. RETRIEVE_FD and FINISH are only valid for incoming session. Calling a incoming ioctl on an outgoing session is invalid and can cause file handlers to run into unexpected errors. For example, a user can create a (outgoing) session, preserve a memfd, and then immediately do a retrieve without doing a kexec in between. This would result in memfd's retrieve handler to run. The handlers expects to be called from a post-kexec context, and will try to do a kho_restore_vmalloc() or kho_restore_folio() to try and restore memory. KHO catches this (thanks to KHO_PAGE_MAGIC) and returns an error, but since this is considered an internal error and KHO throws out a bunch of WARN()s. Associate a type with each ioctl op and validate the type in luo_session_ioctl() before dispatching the ioctl handler to make sure the op is being called for the right session type.
Title liveupdate: validate session type before performing operation
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-08-17T05:05:55.589Z

Reserved: 2026-07-30T09:28:09.395Z

Link: CVE-2026-68455

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-15T06:17:17.160

Modified: 2026-08-17T06:17:54.670

Link: CVE-2026-68455

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-08-15T00:00:00Z

Links: CVE-2026-68455 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-08-18T06:00:04Z

Weaknesses