{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-89709","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-09-11T19:38:34.751Z","datePublished":"2026-09-11T19:46:24.803Z","dateUpdated":"2026-10-30T12:32:47.602Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-10-30T12:32:47.602Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nlockd, nfsd: RCU-protect nlmsvc_ops dispatch\n\nnlmsvc_ops is published by nfsd_lockd_init() and cleared by\nnfsd_lockd_shutdown() with plain stores, while lockd dereferences\nit unguarded from dispatch sites in fs/lockd/svcsubs.c. The pointer\ntargets nfsd's .rodata and the fopen/fclose callbacks live in nfsd's\n.text, so a stale load after rmmod nfsd results in either a NULL\nderef or a module-text use-after-free.\n\nDeclare nlmsvc_ops as __rcu, publish via rcu_assign_pointer(), clear\nvia RCU_INIT_POINTER() + synchronize_rcu(). Add a struct module\n*owner field to nlmsvc_binding and pin the module across indirect\ncalls with try_module_get/module_put. When the binding is torn down,\nfall back to fput() to avoid leaking struct file references."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":8.1,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - lockd is the in-kernel NLM RPC server on TCP/UDP (rpcbind-registered) used with nfsd. nlm_do_fopen() and nlm_delete_file() run from NLM LOCK/TEST/UNLOCK/FREE_ALL in svc_recv, so a remote NFS/NLM peer reaches the unguarded nlmsvc_ops->fopen/fclose dispatch.\nAC:H - The UAF requires exit_nfsd()/rmmod nfsd to NULL nlmsvc_ops with a plain store and free nfsd .text while lockd still dispatches. A remote attacker can flood NLM requests but cannot unload nfsd; that victim-side module teardown is beyond attacker control.\nPR:N - lockd_authenticate() accepts RPC_AUTH_NULL and RPC_AUTH_UNIX before procedure dispatch. nlm_fopen() uses NFSD_MAY_BYPASS_GSS|NFSD_MAY_NLM, and typical exports use AUTH_SYS, so no host account or capability is required.\nUI:N - Exploitation is driven by attacker-sent NLM RPCs to an already-running lockd; no victim user must mount a filesystem or open a file. nfsd unload is an environmental timing condition, not User Interaction.\nS:U - The module-text UAF and NULL deref corrupt host kernel lockd/nfsd state within the same OS security authority and do not cross a VM, IOMMU, or sandbox boundary.\nC:H - After rmmod, a stale nlmsvc_ops load calls fopen/fclose from freed nfsd .rodata/.text. Reclaim of those module pages lets the attacker control the indirect-call target, yielding an arbitrary kernel read per UAF guidance.\nI:H - Indirect call through a dangling nlmsvc_binding in freed nfsd module memory is a RIP-hijack primitive; spraying recycled module pages enables arbitrary kernel write and control-flow hijack, so integrity impact is high.\nA:H - A stale nlmsvc_ops load after rmmod nfsd is either a NULL deref or a call into unmapped module text; both oops/panic the kernel, so availability impact is high."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/lockd/svc.c","fs/lockd/svc4proc.c","fs/lockd/svcproc.c","fs/lockd/svcsubs.c","fs/nfsd/lockd.c","include/linux/lockd/bind.h"],"versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"cc2f0d79b21be69b891cbd1899daf2a1fdf9df87","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"43943532c105ea8fe26039a1347cfda4ac0fcadc","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"6e7495972039f212e336e552b58cac9dd54611c3","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"836ce2b99bcce6d68c58edd04efbc5cd1fd581af","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"3c461a1820088fb5889d73a6522369bde45527a9","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"641e5e20852359b8c31149be4598884e30652f60","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/lockd/svc.c","fs/lockd/svc4proc.c","fs/lockd/svcproc.c","fs/lockd/svcsubs.c","fs/nfsd/lockd.c","include/linux/lockd/bind.h"],"versions":[{"version":"2.6.12","status":"affected"},{"version":"0","lessThan":"2.6.12","status":"unaffected","versionType":"semver"},{"version":"6.1.191","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.160","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.114","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.57","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":"2.6.12","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.6.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.12.114"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.18.57"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"7.2.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"7.3"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/cc2f0d79b21be69b891cbd1899daf2a1fdf9df87"},{"url":"https://git.kernel.org/stable/c/43943532c105ea8fe26039a1347cfda4ac0fcadc"},{"url":"https://git.kernel.org/stable/c/6e7495972039f212e336e552b58cac9dd54611c3"},{"url":"https://git.kernel.org/stable/c/836ce2b99bcce6d68c58edd04efbc5cd1fd581af"},{"url":"https://git.kernel.org/stable/c/3c461a1820088fb5889d73a6522369bde45527a9"},{"url":"https://git.kernel.org/stable/c/641e5e20852359b8c31149be4598884e30652f60"}],"title":"lockd, nfsd: RCU-protect nlmsvc_ops dispatch","x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-89709","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T19:26:23.054440Z"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-10-16T19:36:59.347Z"}}]}}