{"id":"CVE-2026-89539","summary":"SUNRPC: reject duplicate CREDS_VALUE options","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nSUNRPC: reject duplicate CREDS_VALUE options\n\ngssx_dec_option_array() walks the wire-supplied option array and, for\nevery entry whose name matches CREDS_VALUE, calls\ngssx_dec_linux_creds() on the same struct svc_cred. That helper\nunconditionally installs a fresh groups_alloc() result into\ncreds-\u003ecr_group_info without releasing whatever pointer was already\nthere:\n\n    for (i = 0; i \u003c count; i++) {\n        ... decode name ...\n        if (length == sizeof(CREDS_VALUE) &&\n            memcmp(p, CREDS_VALUE, sizeof(CREDS_VALUE)) == 0) {\n            err = gssx_dec_linux_creds(xdr, creds);\n            ...\n        }\n    }\n\nA reply that carries two CREDS_VALUE entries therefore overwrites\ncr_group_info on the second iteration and orphans the group_info\nallocated by the first call. The earlier free_creds path only\nreleases the last cr_group_info via free_svc_cred(), so the first\nallocation's refcount stays at one and its kvmalloc-backed storage\nis leaked. No in-tree caller of gssp_accept_sec_context_upcall()\nexpects more than one CREDS_VALUE per reply.\n\nFix by tracking whether a CREDS_VALUE option has already been\ndecoded and returning -EINVAL on any subsequent match, so the\nfree_creds path releases the single group_info that was installed.","modified":"2026-09-13T03:47:19.284218289Z","published":"2026-09-11T19:44:16.699Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89539.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/2e4ce62385c1b8a887c5370af058ac7b52a8eaf9"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7a1d0501cbb962beba23377035d667bf3c1726ee"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9d94f046b23de0f77849ea69133063c949297e30"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f615b884310bf82d0014e3b5a92eb9aa88146685"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89539.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89539"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"1d658336b05f8697d6445834f8867f8ad5e4f735"},{"fixed":"f615b884310bf82d0014e3b5a92eb9aa88146685"},{"fixed":"7a1d0501cbb962beba23377035d667bf3c1726ee"},{"fixed":"9d94f046b23de0f77849ea69133063c949297e30"},{"fixed":"2e4ce62385c1b8a887c5370af058ac7b52a8eaf9"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89539.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.10.0"},{"fixed":"6.12.109"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.50"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.4"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89539.json"}}],"schema_version":"1.9.0"}