{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-89655", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.743Z", "datePublished": "2026-09-11T19:45:44.841Z", "dateUpdated": "2026-09-11T19:45:44.841Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-09-11T19:45:44.841Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nceph: fix UAF in __kick_flushing_caps() on cf entry freed during unlock\n\nlist_for_each_entry() iterates ci->i_cap_flush_list but drops\ni_ceph_lock to send cap messages. During the unlock window,\nhandle_cap_flush_ack() can acquire i_ceph_lock, detach cf entries\nwith tid <= flush_tid from the list, release i_ceph_lock, and free\nthem via ceph_free_cap_flush() outside any lock. When the original\nthread reacquires i_ceph_lock and the for-loop macro advances via\ncf = list_next_entry(cf, i_list), it dereferences cf->i_list.next\non freed memory.\n\nThe race timeline:\n\n __kick_flushing_caps() handle_cap_flush_ack()\n ----------------------- -----------------------\n holds i_ceph_lock <---\n iterates to cf (tid=10)\n prepares FLUSH message\n drops i_ceph_lock <---\n __send_cap() \u2500\u2500 FLUSH(tid=10)\n\t MDS sends FLUSH_ACK(tid=10)\n ---> acquires i_ceph_lock\n cf->tid(10) <= flush_tid(10),\n detaches cf from i_cap_flush_list\n drops i_ceph_lock\n ceph_free_cap_flush(cf) <- frees it!\n acquires i_ceph_lock <---\n for-loop advances:\n cf = list_next_entry(cf, i_list)\n -- UAF on freed cf->i_list.next\n\nThe cf was just sent by __kick_flushing_caps itself via __send_cap().\nThe MDS may respond with FLUSH_ACK quickly enough that\nhandle_cap_flush_ack() frees cf before __kick_flushing_caps can\nfinish the iteration.\n\nFix by converting to a manual while loop: save the next pointer\nunder i_ceph_lock before dropping it, then use the saved pointer\nafter reacquiring, so the potentially-freed cf is never accessed again."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/ceph/caps.c"], "versions": [{"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "2701431aa3cc8b23efe6890182e7b04f5e76fab5", "status": "affected", "versionType": "git"}, {"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "fe46746087b5b9c5bb2d022df6c7819218494ced", "status": "affected", "versionType": "git"}, {"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "2dba24dcd5050be4b7b119e6f0b01f62203b5d26", "status": "affected", "versionType": "git"}, {"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "7af4c4f01305b0935adf6d4301b1ec407025485d", "status": "affected", "versionType": "git"}, {"version": "0", "lessThan": "6.12.109", "status": "affected", "versionType": "semver"}, {"version": "0", "lessThan": "6.18.50", "status": "affected", "versionType": "semver"}, {"version": "0", "lessThan": "7.2.4", "status": "affected", "versionType": "semver"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/ceph/caps.c"], "versions": [{"version": "6.12.109", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.50", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2.4", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.3-rc1", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionEndExcluding": "6.12.109"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionEndExcluding": "6.18.50"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionEndExcluding": "7.2.4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionEndExcluding": "7.3-rc1"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/2701431aa3cc8b23efe6890182e7b04f5e76fab5"}, {"url": "https://git.kernel.org/stable/c/fe46746087b5b9c5bb2d022df6c7819218494ced"}, {"url": "https://git.kernel.org/stable/c/2dba24dcd5050be4b7b119e6f0b01f62203b5d26"}, {"url": "https://git.kernel.org/stable/c/7af4c4f01305b0935adf6d4301b1ec407025485d"}], "title": "ceph: fix UAF in __kick_flushing_caps() on cf entry freed during unlock", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/ceph/caps.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "2701431aa3cc8b23efe6890182e7b04f5e76fab5", "status": "affected", "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "versionType": "git"}, {"lessThan": "fe46746087b5b9c5bb2d022df6c7819218494ced", "status": "affected", "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "versionType": "git"}, {"lessThan": "2dba24dcd5050be4b7b119e6f0b01f62203b5d26", "status": "affected", "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "versionType": "git"}, {"lessThan": "7af4c4f01305b0935adf6d4301b1ec407025485d", "status": "affected", "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "versionType": "git"}, {"lessThan": "6.12.109", "status": "affected", "version": "0", "versionType": "semver"}, {"lessThan": "6.18.50", "status": "affected", "version": "0", "versionType": "semver"}, {"lessThan": "7.2.4", "status": "affected", "version": "0", "versionType": "semver"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/ceph/caps.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.109", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.50", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.4", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3-rc1", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nceph: fix UAF in __kick_flushing_caps() on cf entry freed during unlock\n\nlist_for_each_entry() iterates ci->i_cap_flush_list but drops\ni_ceph_lock to send cap messages. During the unlock window,\nhandle_cap_flush_ack() can acquire i_ceph_lock, detach cf entries\nwith tid <= flush_tid from the list, release i_ceph_lock, and free\nthem via ceph_free_cap_flush() outside any lock. When the original\nthread reacquires i_ceph_lock and the for-loop macro advances via\ncf = list_next_entry(cf, i_list), it dereferences cf->i_list.next\non freed memory.\n\nThe race timeline:\n\n __kick_flushing_caps() handle_cap_flush_ack()\n ----------------------- -----------------------\n holds i_ceph_lock <---\n iterates to cf (tid=10)\n prepares FLUSH message\n drops i_ceph_lock <---\n __send_cap() \u2500\u2500 FLUSH(tid=10)\n\t MDS sends FLUSH_ACK(tid=10)\n ---> acquires i_ceph_lock\n cf->tid(10) <= flush_tid(10),\n detaches cf from i_cap_flush_list\n drops i_ceph_lock\n ceph_free_cap_flush(cf) <- frees it!\n acquires i_ceph_lock <---\n for-loop advances:\n cf = list_next_entry(cf, i_list)\n -- UAF on freed cf->i_list.next\n\nThe cf was just sent by __kick_flushing_caps itself via __send_cap().\nThe MDS may respond with FLUSH_ACK quickly enough that\nhandle_cap_flush_ack() frees cf before __kick_flushing_caps can\nfinish the iteration.\n\nFix by converting to a manual while loop: save the next pointer\nunder i_ceph_lock before dropping it, then use the saved pointer\nafter reacquiring, so the potentially-freed cf is never accessed again."}], "id": "CVE-2026-89655", "lastModified": "2026-09-11T20:19:51.683", "metrics": {}, "published": "2026-09-11T20:19:51.683", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/2701431aa3cc8b23efe6890182e7b04f5e76fab5"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/2dba24dcd5050be4b7b119e6f0b01f62203b5d26"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/7af4c4f01305b0935adf6d4301b1ec407025485d"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/fe46746087b5b9c5bb2d022df6c7819218494ced"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: ceph: Linux kernel Ceph: Use-After-Free vulnerability in capability message handling", "id": "2532127", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2532127"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.3", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H", "status": "draft"}, "cwe": "CWE-366", "details": ["A flaw was found in the Linux kernel's Ceph file system component. A race condition exists in the `__kick_flushing_caps()` function during the handling of capability messages. This allows a separate process to free a data structure (`cf entry`) while `__kick_flushing_caps()` is still iterating over it. This use-after-free (UAF) vulnerability can lead to system instability, a denial of service (DoS), or potentially privilege escalation for a local attacker."], "name": "CVE-2026-89655", "public_date": "2026-09-11T19:45:44Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-89655\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-89655\nhttps://git.kernel.org/stable/c/2701431aa3cc8b23efe6890182e7b04f5e76fab5\nhttps://git.kernel.org/stable/c/2dba24dcd5050be4b7b119e6f0b01f62203b5d26\nhttps://git.kernel.org/stable/c/7af4c4f01305b0935adf6d4301b1ec407025485d\nhttps://git.kernel.org/stable/c/fe46746087b5b9c5bb2d022df6c7819218494ced"], "threat_severity": "Moderate"}

{}