CVE-2026-52930

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux4c677e2eefdba9c5bfc4474e2e91b26ae8458a1d < b1e9aef48e4d8a0c1b54fb913077b0824ed7d650affected
LinuxLinux4c677e2eefdba9c5bfc4474e2e91b26ae8458a1d < 92cda2593cf2ed25b0e9d78e5e6d8303bba1a064affected
LinuxLinux4c677e2eefdba9c5bfc4474e2e91b26ae8458a1d < 1f0d01e35dbb228084d5187212e32c91a30dcbebaffected
LinuxLinux4c677e2eefdba9c5bfc4474e2e91b26ae8458a1d < 6560be3f6a5bb84f006f184f0c966747bb58e1a3affected
LinuxLinux4c677e2eefdba9c5bfc4474e2e91b26ae8458a1d < b5107b4ce3ad45fcf369ee2058c8910620f4b5a8affected
LinuxLinux4c677e2eefdba9c5bfc4474e2e91b26ae8458a1d < db752ebfdaf2c7f27cd9690ef48b616af068319caffected
LinuxLinux4c677e2eefdba9c5bfc4474e2e91b26ae8458a1d < 030bbc857bd51d4b25a90d931d3f8775ef22823aaffected
LinuxLinux4c677e2eefdba9c5bfc4474e2e91b26ae8458a1d < 2e5c6f4fd4001562781e99bbfc7f1f0127187542affected
LinuxLinux3.1affected
LinuxLinux0 < 3.1unaffected
LinuxLinux5.10.259 <= 5.10.*unaffected
LinuxLinux5.15.210 <= 5.15.*unaffected
LinuxLinux6.1.176 <= 6.1.*unaffected
LinuxLinux6.6.143 <= 6.6.*unaffected
LinuxLinux6.12.94 <= 6.12.*unaffected
LinuxLinux6.18.36 <= 6.18.*unaffected
LinuxLinux7.0.13 <= 7.0.*unaffected
LinuxLinux7.1 <= *unaffected

Weaknesses

References