{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-90067", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.784Z", "datePublished": "2026-09-17T16:05:49.600Z", "dateUpdated": "2026-10-19T08:57:24.503Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:57:24.503Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nlibceph: validate banner payload length\n\nWhen parsing the Ceph messenger v2 protocol banner, the `payload_len` field\nis decoded from the banner prefix. If a client sends a banner with a\n`payload_len` of 0, the kernel sets up a 0-length socket read. This\nviolates an invariant in the state machine, triggering a warning in\n`populate_in_iter()`:\n\n------------[ cut here ]------------\n!iov_iter_count(&con->v2.in_iter)\nWARNING: net/ceph/messenger_v2.c:3129 at populate_in_iter\nnet/ceph/messenger_v2.c:3129 [inline], CPU#1: kworker/1:3/5070\nWARNING: net/ceph/messenger_v2.c:3129 at ceph_con_v2_try_read+0x6634/0x6810\nnet/ceph/messenger_v2.c:3159, CPU#1: kworker/1:3/5070\n...\nCall Trace:\n \n ceph_con_workfn+0x1f5/0x14a0 net/ceph/messenger.c:1575\n process_one_work kernel/workqueue.c:3322 [inline]\n process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405\n worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486\n kthread+0x388/0x470 kernel/kthread.c:436\n ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158\n ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245\n \n\nAccording to the msgr2 protocol specification, the banner payload is\nexpected to contain at least two 64-bit integers (`server_feat` and\n`server_req_feat`). Therefore, `payload_len` must be at least 16 bytes.\n\nFix this by adding a check in `process_banner_prefix()` to reject a\n`payload_len` smaller than 16 bytes. This prevents the 0-length read and\ncorrectly aborts the connection with a protocol error." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - The attacker-controlled field is the 16-bit payload_len in the msgr2 banner prefix (\"ceph v2\\n\" plus le16) that process_banner_prefix() decodes from bytes received by ceph_con_v2_try_read() on the TCP socket opened by ceph_tcp_connect() in ceph_con_v2_try_write(); a remote MON/OSD/MDS peer sends that banner over routable IP.\nAC:L - The TCP peer fully controls the banner prefix and can set payload_len to 0, so prepare_read_banner_payload() installs a zero-length in_iter and populate_in_iter() hits WARN_ON(!iov_iter_count(&con->v2.in_iter)) on every such handshake; no race or layout outside the attacker’s control is required.\nPR:N - process_banner_prefix() runs in CEPH_CON_S_V2_BANNER_PREFIX, before prepare_hello() and before CEPH_CON_S_V2_AUTH, so the malformed payload_len is processed prior to Cephx or any other credential check; the attacker is the remote TCP peer and needs no account on the victim host.\nUI:N - Once a kernel CephFS or RBD client is running, __open_session(), reopen_osd(), and MDS ceph_con_open() automatically TCP-reconnect and ceph_con_workfn() reads the peer banner with no further victim action; a compromised cluster daemon triggers the bug on that reconnect.\nS:U - The WARN_ON in populate_in_iter() and the resulting connection fault remain inside the victim kernel’s libceph messenger and do not cross a VM, IOMMU, or sandbox boundary.\nC:N - A zero payload_len only makes populate_in_iter() WARN and return -ENODATA after prepare_read_banner_payload() sets up an empty in_iter; the path does not perform an out-of-bounds read, UAF, or other kernel-memory disclosure.\nI:N - prepare_read_banner_payload() with payload_len 0 never writes past an allocated buffer, and the failure path only faults the connection; attacker input does not corrupt kernel memory or hijack control flow.\nA:H - WARN_ON(!iov_iter_count(&con->v2.in_iter)) in populate_in_iter() after a zero-length banner payload is an attacker-triggerable kernel warning that panics the host when panic_on_warn is set, and the -ENODATA return through ceph_con_v2_try_read() into con_fault() aborts every msgr2 handshake." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ceph/messenger_v2.c" ], "versions": [ { "version": "cd1a677cad994021b19665ed476aea63f5d54f31", "lessThan": "279c0852999fd2384f4a88155091a99e81f96873", "status": "affected", "versionType": "git" }, { "version": "cd1a677cad994021b19665ed476aea63f5d54f31", "lessThan": "6cf666e47f2b51d5a887ec8a3226cde951757d27", "status": "affected", "versionType": "git" }, { "version": "cd1a677cad994021b19665ed476aea63f5d54f31", "lessThan": "3b2e62a7655d347a845a91155610ddae11daffc6", "status": "affected", "versionType": "git" }, { "version": "cd1a677cad994021b19665ed476aea63f5d54f31", "lessThan": "c1b937ff24b19e69aa7fb1b0f46a74d4c9668692", "status": "affected", "versionType": "git" }, { "version": "cd1a677cad994021b19665ed476aea63f5d54f31", "lessThan": "6d1c6f228854aa89844fd0152d7ed7ac72a55e89", "status": "affected", "versionType": "git" }, { "version": "cd1a677cad994021b19665ed476aea63f5d54f31", "lessThan": "c77633a9595658210a6e216a071e5a396a0835a7", "status": "affected", "versionType": "git" }, { "version": "cd1a677cad994021b19665ed476aea63f5d54f31", "lessThan": "f374967fcdf04001c9b66df1c19106fa83cd91f7", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ceph/messenger_v2.c" ], "versions": [ { "version": "5.11", "status": "affected" }, { "version": "0", "lessThan": "5.11", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.221", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.188", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.157", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.110", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.52", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.6", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "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:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "5.15.221" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "6.1.188" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "6.6.157" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "6.12.110" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "6.18.52" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "7.2.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/279c0852999fd2384f4a88155091a99e81f96873" }, { "url": "https://git.kernel.org/stable/c/6cf666e47f2b51d5a887ec8a3226cde951757d27" }, { "url": "https://git.kernel.org/stable/c/3b2e62a7655d347a845a91155610ddae11daffc6" }, { "url": "https://git.kernel.org/stable/c/c1b937ff24b19e69aa7fb1b0f46a74d4c9668692" }, { "url": "https://git.kernel.org/stable/c/6d1c6f228854aa89844fd0152d7ed7ac72a55e89" }, { "url": "https://git.kernel.org/stable/c/c77633a9595658210a6e216a071e5a396a0835a7" }, { "url": "https://git.kernel.org/stable/c/f374967fcdf04001c9b66df1c19106fa83cd91f7" } ], "title": "libceph: validate banner payload length", "x_generator": { "engine": "bippy-1.2.0" } } } }