{"id":"CVE-2026-89698","summary":"nfsd: widen nfsd_genl_rqstp address fields to sockaddr_storage","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: widen nfsd_genl_rqstp address fields to sockaddr_storage\n\nstruct nfsd_genl_rqstp declares rq_daddr and rq_saddr as plain\n\"struct sockaddr\" (16 bytes). When an IPv6 NFS client is connected,\nnfsd_genl_rpc_status_compose_msg() casts these fields to\n\"struct sockaddr_in6 *\" (28 bytes) and reads sin6_addr at offset 8..24,\nwhich extends 8 bytes past the end of the 16-byte sockaddr field into\nthe adjacent rq_flags member. The 16-byte nla_put_in6_addr then ships 8\nbytes of truncated IPv6 address followed by 8 bytes of rq_flags to\nuserspace via the NFSD_A_RPC_STATUS_SADDR6/DADDR6 netlink attributes.\n\nThis is reachable by any unprivileged process in the network namespace\nbecause NFSD_CMD_RPC_STATUS_GET uses GENL_CMD_CAP_DUMP without\nGENL_ADMIN_PERM.\n\nFix by widening rq_daddr and rq_saddr to struct sockaddr_storage so the\nIPv6 casts operate within bounds, copying sizeof(struct sockaddr_storage)\nbytes in the memcpy calls so the full address is captured, and\nzero-initializing the genl_rqstp stack variable to prevent leaking\nuninitialized tail bytes through netlink.","modified":"2026-09-13T03:46:33.714334361Z","published":"2026-09-11T19:46:16.551Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89698.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/03c512f22d3fbe7a3767d6df5e3d88b8e7c105e5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a99d720ed2a5258564e5e9d5f39f3184a030d354"},{"type":"WEB","url":"https://git.kernel.org/stable/c/dcb69ad0dafb4a24b825183bb94055d5be8a10bd"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89698.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89698"},{"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":"bd9d6a3efa9709e653aafbeb859289feccb8e70c"},{"fixed":"03c512f22d3fbe7a3767d6df5e3d88b8e7c105e5"},{"fixed":"dcb69ad0dafb4a24b825183bb94055d5be8a10bd"},{"fixed":"a99d720ed2a5258564e5e9d5f39f3184a030d354"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89698.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.18.51"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.4"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89698.json"}}],"schema_version":"1.9.0"}