{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-89684", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.748Z", "datePublished": "2026-09-11T19:46:06.374Z", "dateUpdated": "2026-10-19T08:50:57.622Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:50:57.622Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix cpntf publish race in nfs4_init_cp_state\n\nnfs4_alloc_init_cpntf_state() published the new cpntf entry into the\ns2s_cp_stateids IDR (with cs_type set) in one s2s_cp_lock section, then\ntook the lock again to list_add() it onto p_stid->sc_cp_list. In the gap\nthe entry is reachable by so_id but cp_list is still {NULL,NULL} from\nkzalloc. A racing OFFLOAD_CANCEL (so_id is echoed to the client as\ncnr_stateid, so any NFSv4.2 client can drive it) reaches\nmanage_cpntf_state() -> _free_cpntf_state_locked() and does list_del() on\nthe zeroed list_head, oopsing the server.\n\nFold the cs_type assignment and the list_add() into the same critical\nsection as idr_alloc_cyclic(), so a concurrent lookup either misses the\nentry or sees a fully linked cp_list. INIT_LIST_HEAD() the entry after\nallocation and switch _free_cpntf_state_locked() to list_del_init() so a\nstale unlink is a no-op. nfs4_init_copy_state() passes NULL p_stid and\nskips the list_add, preserving NFS4_COPY_STID semantics." } ], "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 flaw is in nfsd NFSv4.2 COPY_NOTIFY/OFFLOAD_CANCEL (nfsd4_copy_notify, nfs4_alloc_init_cpntf_state, manage_cpntf_state). Compounds reach nfsd4_proc_compound via svc_process on TCP/2049, so a remote NFS client triggers the published cpntf IDR entry over the network.\nAC:L - The attacker drives both sides: COPY_NOTIFY publishes the cpntf into s2s_cp_stateids while a concurrent OFFLOAD_CANCEL uses the leaked s2s_cp_cl_id and cyclic so_id to list_del the still-zeroed cp_list. The window is retryable on multiple session slots with no victim-controlled state.\nPR:N - Default AUTH_SYS/AUTH_NULL nfsd exports do no cryptographic authentication. Any host allowed by the export ACL can EXCHANGE_ID/CREATE_SESSION, OPEN a readable file, and issue COPY_NOTIFY and OFFLOAD_CANCEL; no local account or capability on the NFS server is required.\nUI:N - The attacking NFS client sends COPY_NOTIFY and the concurrent OFFLOAD_CANCEL itself; no victim user or administrator action on the NFS server is required at attack time.\nS:U - list_del of the uninitialized cp_list oopses an nfsd worker in the host kernel copy-notify tables. Impact stays in that kernel security authority and does not cross a VM, IOMMU, or sandbox boundary.\nC:N - The race is list_del on a kzalloc'd nfs4_cpntf_state.cp_list still {NULL,NULL}, a NULL-pointer dereference in __list_del. It oopses without reading kernel memory or providing an information-disclosure primitive.\nI:N - The only write is next->prev/prev->next through NULL list pointers from kzalloc; a remote NFS client cannot map the NULL page, so this is not a kernel write or control-flow hijack primitive.\nA:H - list_del on the zeroed list_head oopses or panics the nfsd thread (and can leak s2s_cp_lock). The attacker can repeat the concurrent COMPOUND sequence to deny NFS service and take down the server." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/nfsd/nfs4state.c" ], "versions": [ { "version": "624322f1adc58acd0b69f77a6ddc764207e97241", "lessThan": "63e18fc65587fd3f7b4c6d70e96d32fc41d82ba3", "status": "affected", "versionType": "git" }, { "version": "624322f1adc58acd0b69f77a6ddc764207e97241", "lessThan": "6ac469a274e3c7d87fc46ba46d83b95009680407", "status": "affected", "versionType": "git" }, { "version": "624322f1adc58acd0b69f77a6ddc764207e97241", "lessThan": "8eeca993357a0bc35aaefebfd7462ac7b0a21d9a", "status": "affected", "versionType": "git" }, { "version": "624322f1adc58acd0b69f77a6ddc764207e97241", "lessThan": "bfeac42d9074e539bacd1898dd8c14b7f5776620", "status": "affected", "versionType": "git" }, { "version": "624322f1adc58acd0b69f77a6ddc764207e97241", "lessThan": "21d6c5957f5ca97d7352e60f55ea412beb9419f5", "status": "affected", "versionType": "git" }, { "version": "624322f1adc58acd0b69f77a6ddc764207e97241", "lessThan": "a631a26a8777bb235eabd478bbbaf26a4db750bf", "status": "affected", "versionType": "git" }, { "version": "624322f1adc58acd0b69f77a6ddc764207e97241", "lessThan": "c7270f62e7a05a2ee68aa2b74262b658a14463bd", "status": "affected", "versionType": "git" }, { "version": "624322f1adc58acd0b69f77a6ddc764207e97241", "lessThan": "be3a5c1d857b0dcbc11796cea603ef25834f75b2", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/nfsd/nfs4state.c" ], "versions": [ { "version": "5.6", "status": "affected" }, { "version": "0", "lessThan": "5.6", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.270", "lessThanOrEqual": "5.10.*", "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": "6.12.109", "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", "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": "5.6", "versionEndExcluding": "5.10.270" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "5.15.221" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "6.1.188" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "6.6.157" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "6.12.109" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "6.18.50" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "7.2.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/63e18fc65587fd3f7b4c6d70e96d32fc41d82ba3" }, { "url": "https://git.kernel.org/stable/c/6ac469a274e3c7d87fc46ba46d83b95009680407" }, { "url": "https://git.kernel.org/stable/c/8eeca993357a0bc35aaefebfd7462ac7b0a21d9a" }, { "url": "https://git.kernel.org/stable/c/bfeac42d9074e539bacd1898dd8c14b7f5776620" }, { "url": "https://git.kernel.org/stable/c/21d6c5957f5ca97d7352e60f55ea412beb9419f5" }, { "url": "https://git.kernel.org/stable/c/a631a26a8777bb235eabd478bbbaf26a4db750bf" }, { "url": "https://git.kernel.org/stable/c/c7270f62e7a05a2ee68aa2b74262b658a14463bd" }, { "url": "https://git.kernel.org/stable/c/be3a5c1d857b0dcbc11796cea603ef25834f75b2" } ], "title": "nfsd: fix cpntf publish race in nfs4_init_cp_state", "x_generator": { "engine": "bippy-1.2.0" } } } }