Copyright © 2012 Red Hat, Inc. All rights reserved. Moderate 2026-06-24T00:00:00 kernel: ipc/shm: serialize orphan cleanup with shm_nattch updates 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CWE-367

In the Linux kernel, the following vulnerability has been resolved: ipc/shm: serialize orphan cleanup with shm_nattch updates shm_destroy_orphaned() walks the shm idr under shm_ids(ns).rwsem, but that does not serialize all fields tested by shm_may_destroy(). In particular, shm_nattch is updated while holding shm_perm.lock, and attach paths can do that without holding the rwsem. Do not decide that an orphaned segment is unused before taking the object lock. Move the shm_may_destroy() check under shm_perm.lock, matching the other destroy paths, and unlock the segment when it no longer qualifies for removal.

A flaw was found in the Linux kernel's inter-process communication (IPC) shared memory (shm) component. A synchronization issue exists where orphaned shared memory segments might be incorrectly destroyed while still in use due to a lack of serialization between cleanup and attachment updates. This could lead to system instability or a denial of service.

Red Hat Enterprise Linux 10 Affected kernel Red Hat Enterprise Linux 6 Out of support scope kernel Red Hat Enterprise Linux 7 Affected kernel Red Hat Enterprise Linux 7 Affected kernel-rt Red Hat Enterprise Linux 8 Affected kernel Red Hat Enterprise Linux 8 Affected kernel-rt Red Hat Enterprise Linux 9 Affected kernel Red Hat Enterprise Linux 9 Affected kernel-rt https://www.cve.org/CVERecord?id=CVE-2026-52930 https://nvd.nist.gov/vuln/detail/CVE-2026-52930 https://lore.kernel.org/linux-cve-announce/2026062432-CVE-2026-52930-9f00@gregkh/T