{"id":"CVE-2026-89690","revision":"b865c25ea4d5449ca8e092e6e032c0d3","records":[{"revision":"b865c25ea4d5449ca8e092e6e032c0d3","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-89690","aliases":[],"title":"nfsd: defer vfree of compound ops to fix rpc_status UAF","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: defer vfree of compound ops to fix rpc_status UAF\n\nThe rpc_status netlink dumpit walks every in-flight svc_rqst under\nrcu_read_lock and, for NFSv4 requests, reads opnums out of\nargs->ops[]. But args->ops is a separate vmalloc buffer freed\nsynchronously by vfree() in nfsd4_release_compoundargs() at the end\nof every compound. The dumpit's rcu_read_lock pins the svc_rqst\nstruct itself (freed via kfree_rcu), but nothing defers the vfree\nof the ops buffer across the RCU grace period. A concurrent compound\ncompletion can therefore free the buffer while the dumpit is reading\nit — a use-after-free on vmalloc memory.\n\nThe trailing seqcount recheck (smp_load_acquire of rq_status_counter)\ncannot undo a load that already retired against freed memory.\n\nFix by replacing vfree(args->ops) with kvfree_rcu_mightsleep(), which\ndefers the free until after an RCU grace period. This makes the\nexisting rcu_read_lock in the dumpit sufficient to protect the read.\nThe tradeoff is that completed compound ops buffers (up to\n200 * sizeof(struct nfsd4_op)) persist in memory slightly longer,\nacross one grace period, before being reclaimed.","state":0,"publishedAt":"2026-09-11T19:46:10.632+00:00","modifiedAt":"2026-10-19T08:51:03.524+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"fs/nfsd/nfs4xdr.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"bd9d6a3efa9709e653aafbeb859289feccb8e70c\",\n                            \"lessThan\": \"48f72aff24f7a7329209dc6cbc27c869f3e3595c\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"bd9d6a3efa9709e653aafbeb859289feccb8e70c\",\n                            \"lessThan\": \"6703199f4d7e7f37d6a726a849eb358e8fae72fb\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"bd9d6a3efa9709e653aafbeb859289feccb8e70c\",\n                            \"lessThan\": \"19413ccc45070a7270b9e25c2a258daf7f91de42\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"bd9d6a3efa9709e653aafbeb859289feccb8e70c\",\n                            \"lessThan\": \"fca26a3fc19ed02278aa2a150af82d43db0302cb\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"fs/nfsd/nfs4xdr.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.7\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.7\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.109\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.50\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.4\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/48f72aff24f7a7329209dc6cbc27c869f3e3595c","https://git.kernel.org/stable/c/6703199f4d7e7f37d6a726a849eb358e8fae72fb","https://git.kernel.org/stable/c/19413ccc45070a7270b9e25c2a258daf7f91de42","https://git.kernel.org/stable/c/fca26a3fc19ed02278aa2a150af82d43db0302cb"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89690","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-89690","identifiers":["CVE-2026-89690"]},"retained":false,"historicalAffected":[]}],"coverage":[]}