{"id":"CVE-2026-89646","revision":"88d50116337e42c6a8922ad17bf3dfac","records":[{"revision":"88d50116337e42c6a8922ad17bf3dfac","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-89646","aliases":[],"title":"ceph: fix leaked inode reference on writeback abort at umount","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nceph: fix leaked inode reference on writeback abort at umount\n\nceph_dirty_folio() takes a wrbuffer claim on each newly dirtied folio: it\nbumps i_wrbuffer_ref (taking an ihold() on the 0->1 transition) and\nattaches the snap_context to folio->private.  That claim is released only\nby ceph_put_wrbuffer_cap_refs(), which for a submitted write runs from\nwritepages_finish().\n\nIn ceph_submit_write(), if ceph_inc_osd_stopping_blocker() fails -- which\nhappens during umount -- the request is aborted before submission: the\nalready-collected folios are only redirtied and unlocked, so\nwritepages_finish() never runs and the claim is leaked.\nredirty_page_for_writepage() -> folio_redirty_for_writepage() ->\nfilemap_dirty_folio() sets PG_dirty directly and does not go through\n->dirty_folio, so ceph_dirty_folio() is not re-entered to rebalance it.\nBecause every subsequent writeback also fails the osd_stopping_blocker,\ni_wrbuffer_ref never returns to 0, the ihold() is never dropped, and the\ninode cannot be evicted:\n\n  VFS: Busy inodes after unmount of ceph\n  kernel BUG at fs/super.c:650!\n\nRelease the orphaned claim in the abort path before redirtying, via\nceph_undo_wrbuffer_claim(): detach the snap_context, drop the wrbuffer\nreference (letting i_wrbuffer_ref reach 0 and iput() the inode), and drop\nthe snap_context reference -- i.e. do what writepages_finish() would have\ndone for these never-submitted folios.\n\nOnly the locked_pages entries are undone; folios still in the fbatch were\nnever dirty-cleared by this call (folio_clear_dirty_for_io() is the\nownership-transfer point, and a successful move NULLs the fbatch slot), so\nthey hold no claim this call owns.","state":0,"publishedAt":"2026-09-11T19:45:37.767+00:00","modifiedAt":"2026-10-19T08:50:17.976+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"fs/ceph/addr.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"fd7449d937e7fb3144770592927cf452bf66dbd3\",\n                            \"lessThan\": \"ec32015a955c5d326c5e26610edfdcccd52f2314\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"fd7449d937e7fb3144770592927cf452bf66dbd3\",\n                            \"lessThan\": \"ac7a5a5385762df458d10cccc086a4e079be7409\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"fd7449d937e7fb3144770592927cf452bf66dbd3\",\n                            \"lessThan\": \"c25aee9c630fb86f98d79eccb75765067079b972\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"fs/ceph/addr.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.15\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.15\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.50\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.4\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/ec32015a955c5d326c5e26610edfdcccd52f2314","https://git.kernel.org/stable/c/ac7a5a5385762df458d10cccc086a4e079be7409","https://git.kernel.org/stable/c/c25aee9c630fb86f98d79eccb75765067079b972"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89646","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-89646","identifiers":["CVE-2026-89646"]},"retained":false,"historicalAffected":[]}],"coverage":[]}