{"id":"CVE-2026-52930","state":"PUBLISHED","title":"ipc/shm: serialize orphan cleanup with shm_nattch updates","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nipc/shm: serialize orphan cleanup with shm_nattch updates\n\nshm_destroy_orphaned() walks the shm idr under shm_ids(ns).rwsem, but that\ndoes not serialize all fields tested by shm_may_destroy().  In particular,\nshm_nattch is updated while holding shm_perm.lock, and attach paths can do\nthat without holding the rwsem.\n\nDo not decide that an orphaned segment is unused before taking the object\nlock.  Move the shm_may_destroy() check under shm_perm.lock, matching the\nother destroy paths, and unlock the segment when it no longer qualifies\nfor removal.","publishedAt":"2026-06-24T07:14:22.704Z","updatedAt":"2026-10-15T01:21:54.648Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4c677e2eefdba9c5bfc4474e2e91b26ae8458a1d","status":"affected","lessThan":"b1e9aef48e4d8a0c1b54fb913077b0824ed7d650","versionType":"git"},{"version":"4c677e2eefdba9c5bfc4474e2e91b26ae8458a1d","status":"affected","lessThan":"92cda2593cf2ed25b0e9d78e5e6d8303bba1a064","versionType":"git"},{"version":"4c677e2eefdba9c5bfc4474e2e91b26ae8458a1d","status":"affected","lessThan":"1f0d01e35dbb228084d5187212e32c91a30dcbeb","versionType":"git"},{"version":"4c677e2eefdba9c5bfc4474e2e91b26ae8458a1d","status":"affected","lessThan":"6560be3f6a5bb84f006f184f0c966747bb58e1a3","versionType":"git"},{"version":"4c677e2eefdba9c5bfc4474e2e91b26ae8458a1d","status":"affected","lessThan":"b5107b4ce3ad45fcf369ee2058c8910620f4b5a8","versionType":"git"},{"version":"4c677e2eefdba9c5bfc4474e2e91b26ae8458a1d","status":"affected","lessThan":"db752ebfdaf2c7f27cd9690ef48b616af068319c","versionType":"git"},{"version":"4c677e2eefdba9c5bfc4474e2e91b26ae8458a1d","status":"affected","lessThan":"030bbc857bd51d4b25a90d931d3f8775ef22823a","versionType":"git"},{"version":"4c677e2eefdba9c5bfc4474e2e91b26ae8458a1d","status":"affected","lessThan":"2e5c6f4fd4001562781e99bbfc7f1f0127187542","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["ipc/shm.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.1","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.1","versionType":"semver"},{"version":"5.10.259","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.210","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.176","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.143","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.94","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.36","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.13","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["ipc/shm.c"]}],"references":["https://git.kernel.org/stable/c/b1e9aef48e4d8a0c1b54fb913077b0824ed7d650","https://git.kernel.org/stable/c/92cda2593cf2ed25b0e9d78e5e6d8303bba1a064","https://git.kernel.org/stable/c/1f0d01e35dbb228084d5187212e32c91a30dcbeb","https://git.kernel.org/stable/c/6560be3f6a5bb84f006f184f0c966747bb58e1a3","https://git.kernel.org/stable/c/b5107b4ce3ad45fcf369ee2058c8910620f4b5a8","https://git.kernel.org/stable/c/db752ebfdaf2c7f27cd9690ef48b616af068319c","https://git.kernel.org/stable/c/030bbc857bd51d4b25a90d931d3f8775ef22823a","https://git.kernel.org/stable/c/2e5c6f4fd4001562781e99bbfc7f1f0127187542","https://cert-portal.siemens.com/productcert/html/ssa-019113.html","https://cert-portal.siemens.com/productcert/html/ssa-457936.html","https://cert-portal.siemens.com/productcert/html/ssa-784472.html"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:16.098Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/52xxx/CVE-2026-52930.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-52930","state":"PUBLISHED","datePublished":"2026-06-24T07:14:22.704Z","dateUpdated":"2026-10-15T01:21:54.648Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-06-09T07:44:35.369Z"},"containers":{"cna":{"title":"ipc/shm: serialize orphan cleanup with shm_nattch updates","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nipc/shm: serialize orphan cleanup with shm_nattch updates\n\nshm_destroy_orphaned() walks the shm idr under shm_ids(ns).rwsem, but that\ndoes not serialize all fields tested by shm_may_destroy().  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