{"id":"CVE-2026-23136","state":"PUBLISHED","title":"libceph: reset sparse-read state in osd_fault()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nlibceph: reset sparse-read state in osd_fault()\n\nWhen a fault occurs, the connection is abandoned, reestablished, and any\npending operations are retried. The OSD client tracks the progress of a\nsparse-read reply using a separate state machine, largely independent of\nthe messenger's state.\n\nIf a connection is lost mid-payload or the sparse-read state machine\nreturns an error, the sparse-read state is not reset. The OSD client\nwill then interpret the beginning of a new reply as the continuation of\nthe old one. If this makes the sparse-read machinery enter a failure\nstate, it may never recover, producing loops like:\n\n  libceph:  [0] got 0 extents\n  libceph: data len 142248331 != extent len 0\n  libceph: osd0 (1)...:6801 socket error on read\n  libceph: data len 142248331 != extent len 0\n  libceph: osd0 (1)...:6801 socket error on read\n\nTherefore, reset the sparse-read state in osd_fault(), ensuring retries\nstart from a clean state.","publishedAt":"2026-02-14T15:22:21.952Z","updatedAt":"2026-10-19T18:25:32.994Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"f628d799972799023d32c2542bb2639eb8c4f84e","status":"affected","lessThan":"90a60fe61908afa0eaf7f8fcf1421b9b50e5f7ff","versionType":"git"},{"version":"f628d799972799023d32c2542bb2639eb8c4f84e","status":"affected","lessThan":"e94075e950a6598e710b9f7dffea5aa388f40313","versionType":"git"},{"version":"f628d799972799023d32c2542bb2639eb8c4f84e","status":"affected","lessThan":"10b7c72810364226f7b27916ea3e2a4f870bc04b","versionType":"git"},{"version":"f628d799972799023d32c2542bb2639eb8c4f84e","status":"affected","lessThan":"11194b416ef95012c2cfe5f546d71af07b639e93","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ceph/osd_client.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.6","versionType":"semver"},{"version":"6.6.121","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.66","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.6","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ceph/osd_client.c"]}],"references":["https://git.kernel.org/stable/c/90a60fe61908afa0eaf7f8fcf1421b9b50e5f7ff","https://git.kernel.org/stable/c/e94075e950a6598e710b9f7dffea5aa388f40313","https://git.kernel.org/stable/c/10b7c72810364226f7b27916ea3e2a4f870bc04b","https://git.kernel.org/stable/c/11194b416ef95012c2cfe5f546d71af07b639e93"],"weaknesses":["CWE-667"],"ingestedAt":"2026-10-29T20:11:21.040Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/23xxx/CVE-2026-23136.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-23136","state":"PUBLISHED","datePublished":"2026-02-14T15:22:21.952Z","dateUpdated":"2026-10-19T18:25:32.994Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-01-13T15:37:45.971Z"},"containers":{"cna":{"title":"libceph: reset sparse-read state in osd_fault()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nlibceph: reset sparse-read state in osd_fault()\n\nWhen a fault occurs, the connection is abandoned, reestablished, and any\npending operations are retried. The OSD client tracks the progress of a\nsparse-read reply using a separate state machine, largely independent of\nthe messenger's state.\n\nIf a connection is lost mid-payload or the sparse-read state machine\nreturns an error, the sparse-read state is not reset. The OSD client\nwill then interpret the beginning of a new reply as the continuation of\nthe old one. If this makes the sparse-read machinery enter a failure\nstate, it may never recover, producing loops like:\n\n  libceph:  [0] got 0 extents\n  libceph: data len 142248331 != extent len 0\n  libceph: osd0 (1)...:6801 socket error on read\n  libceph: data len 142248331 != extent len 0\n  libceph: osd0 (1)...:6801 socket error on read\n\nTherefore, reset the sparse-read state in osd_fault(), ensuring retries\nstart from a clean state."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"f628d799972799023d32c2542bb2639eb8c4f84e","status":"affected","lessThan":"90a60fe61908afa0eaf7f8fcf1421b9b50e5f7ff","versionType":"git"},{"version":"f628d799972799023d32c2542bb2639eb8c4f84e","status":"affected","lessThan":"e94075e950a6598e710b9f7dffea5aa388f40313","versionType":"git"},{"version":"f628d799972799023d32c2542bb2639eb8c4f84e","status":"affected","lessThan":"10b7c72810364226f7b27916ea3e2a4f870bc04b","versionType":"git"},{"version":"f628d799972799023d32c2542bb2639eb8c4f84e","status":"affected","lessThan":"11194b416ef95012c2cfe5f546d71af07b639e93","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ceph/osd_client.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.6","versionType":"semver"},{"version":"6.6.121","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.66","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.6","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ceph/osd_client.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/90a60fe61908afa0eaf7f8fcf1421b9b50e5f7ff"},{"url":"https://git.kernel.org/stable/c/e94075e950a6598e710b9f7dffea5aa388f40313"},{"url":"https://git.kernel.org/stable/c/10b7c72810364226f7b27916ea3e2a4f870bc04b"},{"url":"https://git.kernel.org/stable/c/11194b416ef95012c2cfe5f546d71af07b639e93"}],"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 Ceph OSD client communicates with OSD servers over TCP. A network-level attacker who can disrupt the TCP connection (RST injection) or a malicious/compromised OSD server can trigger the fault during a sparse read operation remotely.\nAC:L - Sparse reads are a normal part of CephFS/RBD operation. An attacker who can disrupt TCP connections can repeatedly do so until one coincides with a sparse read. A malicious OSD server knows exactly when sparse reads are in progress and can reliably trigger the fault.\nPR:N - The attack requires disrupting the TCP connection between client and OSD, which does not require any Ceph authentication credentials. TCP RST injection or network-level connection disruption bypasses CephX authentication entirely.\nUI:N - No user interaction is required. The sparse read operations occur as part of normal CephFS/RBD I/O, and the connection fault is triggered by the attacker without any victim action.\nS:U - The impact is confined to the kernel's Ceph client losing access to the OSD. There is no cross-boundary impact such as VM escape or sandbox escape.\nC:N - The vulnerability causes a data parsing mismatch that is caught by validation checks, returning clean errors. No information disclosure occurs — the stale state causes misinterpretation of reply framing, not exposure of memory contents.\nI:N - No data modification or memory corruption occurs. The validation checks in the sparse read state machine detect the mismatch and return -EREMOTEIO before any data is written to incorrect locations.\nA:H - The OSD connection enters an infinite, unrecoverable error loop where every retry fails with the same stale state mismatch. All CephFS/RBD I/O to the affected OSD hangs or fails indefinitely, causing persistent denial of service."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:20:20.637Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6","versionEndExcluding":"6.6.121"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6","versionEndExcluding":"6.12.66"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6","versionEndExcluding":"6.18.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6","versionEndExcluding":"6.19"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-23136","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-10-16T15:06:32.045794Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-667","lang":"en","type":"CWE","description":"CWE-667 Improper Locking"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T18:25:32.994Z"}}]}}}