{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-89545", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.722Z", "datePublished": "2026-09-11T19:44:21.161Z", "dateUpdated": "2026-10-19T08:48:36.955Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:48:36.955Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsunrpc: defer rq_argp and rq_resp free until after RCU grace period\n\nsvc_rqst_free() frees rqstp->rq_argp and rqstp->rq_resp synchronously\nvia kfree(), but defers the rqstp struct free via kfree_rcu(). After\nsvc_exit_thread() calls list_del_rcu() and svc_rqst_free(), there is\na window where RCU readers that started before list_del_rcu() can still\ntraverse the thread list and find the rqstp. These readers (e.g.\nnfsd_nl_rpc_status_get_dumpit()) dereference rqstp->rq_argp, which has\nalready been freed — a use-after-free.\n\nFix this by moving the kfree of rq_argp and rq_resp into an explicit\ncall_rcu() callback alongside the struct free. Resources not accessed\nby RCU readers (bvec, buffer pages, scratch folio, auth_data) remain\nsynchronously freed." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The use-after-free is reached by NFSD_CMD_RPC_STATUS_GET, a generic-netlink dump over AF_NETLINK that walks svc_rqst threads and reads rq_argp; remote NFS RPCs never enter nfsd_nl_rpc_status_get_dumpit().\nAC:L - The attacker fully controls the dumpit reader and can loop it while nfsd threads exit (dynamic idle-timeout kills or thread-count changes), and can further churn threads with NFS traffic; this is an attacker-driven RCU race, not a condition beyond their control.\nPR:L - NFSD_CMD_RPC_STATUS_GET is registered with GENL_CMD_CAP_DUMP and no GENL_ADMIN_PERM, so any unprivileged process in the nfsd network namespace can invoke the dump; exploiting it does not require CAP_NET_ADMIN or root.\nUI:N - The attacker issues the netlink dump themselves; no separate victim action such as mounting a filesystem or opening a device is required.\nS:U - This is a kernel-heap use-after-free in sunrpc/nfsd on the local host; impact stays inside the kernel's security authority and does not cross a VM, IOMMU, or other security boundary.\nC:H - dumpit dereferences the kfree'd rq_argp (nfsd4_compoundargs) and reads opcnt/opnums under rcu_read_lock; a kernel UAF with heap reuse of that object yields an arbitrary read primitive.\nI:H - The same slab UAF is heap-sprayable so a replaced rq_argp can make dumpit walk attacker-controlled args->ops[], enabling kernel memory corruption and control-flow hijacking.\nA:H - Use-after-free of rq_argp while an RCU reader still holds the svc_rqst from sp_all_threads can oops or panic the kernel even if the UAF is not fully turned into code execution." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sunrpc/svc.c" ], "versions": [ { "version": "812443865c5fc255363d4a684a62c086af1addca", "lessThan": "0ea49d69aa806008b2424c8cf21cf746b9963967", "status": "affected", "versionType": "git" }, { "version": "812443865c5fc255363d4a684a62c086af1addca", "lessThan": "08bc49e0541260bf294962cf889a32a2d2713ad6", "status": "affected", "versionType": "git" }, { "version": "812443865c5fc255363d4a684a62c086af1addca", "lessThan": "e0c5693d3f9a5d4911735ab0e0eba4eecb1f1090", "status": "affected", "versionType": "git" }, { "version": "812443865c5fc255363d4a684a62c086af1addca", "lessThan": "c479bde671cbe2f9e152834a8b0eb7c3c295bbaf", "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/sunrpc/svc.c" ], "versions": [ { "version": "3.19", "status": "affected" }, { "version": "0", "lessThan": "3.19", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.111", "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": "3.19", "versionEndExcluding": "6.12.111" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.19", "versionEndExcluding": "6.18.50" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.19", "versionEndExcluding": "7.2.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.19", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/0ea49d69aa806008b2424c8cf21cf746b9963967" }, { "url": "https://git.kernel.org/stable/c/08bc49e0541260bf294962cf889a32a2d2713ad6" }, { "url": "https://git.kernel.org/stable/c/e0c5693d3f9a5d4911735ab0e0eba4eecb1f1090" }, { "url": "https://git.kernel.org/stable/c/c479bde671cbe2f9e152834a8b0eb7c3c295bbaf" } ], "title": "sunrpc: defer rq_argp and rq_resp free until after RCU grace period", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2026-89545", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2026-10-16T19:23:36.292382Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:26:42.664Z" } } ] } }