Copyright © 2012 Red Hat, Inc. All rights reserved. Moderate 2026-08-15T00:00:00 kernel: liveupdate: validate session type before performing operation 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CWE-1287

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.

A flaw was found in the Linux kernel's liveupdate component. This vulnerability arises from insufficient validation of session types during `ioctl` operations. A local user can exploit this by attempting an `ioctl` operation intended for an incoming session on an outgoing session. This improper handling can lead to unexpected errors in file handlers and trigger numerous kernel warnings, potentially causing system instability and a denial of service.

Red Hat Enterprise Linux 10 Not affected kernel Red Hat Enterprise Linux 6 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel-rt Red Hat Enterprise Linux 8 Not affected kernel Red Hat Enterprise Linux 8 Not affected kernel-rt Red Hat Enterprise Linux 9 Not affected kernel Red Hat Enterprise Linux 9 Not affected kernel-rt https://www.cve.org/CVERecord?id=CVE-2026-68455 https://nvd.nist.gov/vuln/detail/CVE-2026-68455 https://lore.kernel.org/linux-cve-announce/2026081559-CVE-2026-68455-e03a@gregkh/T