{"id":"CVE-2026-89784","summary":"SUNRPC: check rpc_sockaddr2uaddr() return value in rpcb_register_inet4/6","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nSUNRPC: check rpc_sockaddr2uaddr() return value in rpcb_register_inet4/6\n\nrpcb_register_inet4() and rpcb_register_inet6() store the result of\nrpc_sockaddr2uaddr() into map-\u003er_addr without checking it for NULL.\nrpc_sockaddr2uaddr() returns NULL when its final kstrdup() fails, and\nthe unchecked NULL is then carried into the synchronous RPCBPROC_SET\nencode path: rpcb_register_call() -\u003e rpc_call_sync() -\u003e\nrpcb_enc_getaddr() -\u003e encode_rpcb_string(), whose first statement is\nstrlen(string), dereferencing NULL and oopsing the kernel.\n\nThe crash reproduces under failslab on v6.12; with KASAN the NULL\ndereference surfaces as a fault on the shadow of address zero:\n\n Oops: general protection fault, probably for non-canonical address\n       0xdffffc0000000000 [#1] PREEMPT SMP KASAN\n RIP: 0010:strlen (lib/string.c:409)\n Call Trace:\n  encode_rpcb_string (net/sunrpc/rpcb_clnt.c:890)\n  rpcb_enc_getaddr (net/sunrpc/rpcb_clnt.c:910)\n  rpcauth_wrap_req_encode (net/sunrpc/auth.c:745)\n  call_encode (net/sunrpc/clnt.c:1966)\n  __rpc_execute (net/sunrpc/sched.c:952)\n  rpc_run_task (net/sunrpc/clnt.c:1243)\n  rpc_call_sync (net/sunrpc/clnt.c:1272)\n  rpcb_v4_register (net/sunrpc/rpcb_clnt.c:500)\n  svc_generic_rpcbind_set\n  nfsd_rpcbind_set\n  svc_register\n  svc_setup_socket\n  svc_addsock\n  write_ports\n  nfsctl_transaction_write\n  vfs_write\n\nThe crash is reachable when an in-kernel RPC service (nfsd, lockd,\nnfs-callback) registers with the local rpcbind under enough memory\npressure for the small GFP_KERNEL kstrdup() in rpc_sockaddr2uaddr() to\nfail. The asynchronous getport path already handles this exact failure\nmode by returning -ENOMEM; only the two register helpers omit the check.\n\nMirror that handling: bail out with -ENOMEM when rpc_sockaddr2uaddr()\nreturns NULL, before the address is fed into the encoder.","modified":"2026-09-17T03:47:22.469717475Z","published":"2026-09-16T08:48:22.404Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89784.json","cna_assigner":"Linux"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/04441b792ec40eb66349b5fab34b6a2090b5b2dd"},{"type":"WEB","url":"https://git.kernel.org/stable/c/12bf3e0182ccdaf3b412756a756d3944a7dacaa9"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4a6095de8cb1858e05bdf70b3e7d6d7645c25041"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4e01022974355732e748ec8ebc97c558cb624ffe"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5a51c49ddb37b883566874aecc66bc5a2e617a96"},{"type":"WEB","url":"https://git.kernel.org/stable/c/cda4aacfb0bbf5c0f90fd0b42c72c749635d1368"},{"type":"WEB","url":"https://git.kernel.org/stable/c/eb476289c12cc22c8766f8a84eeb7ab46c4e8fb6"},{"type":"WEB","url":"https://git.kernel.org/stable/c/fd22370226a0d8109045d0831fd5aaadee921693"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89784.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89784"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"d77385f23830ee6c400569bac8b37e6eb3b7d360"},{"fixed":"04441b792ec40eb66349b5fab34b6a2090b5b2dd"},{"fixed":"5a51c49ddb37b883566874aecc66bc5a2e617a96"},{"fixed":"4a6095de8cb1858e05bdf70b3e7d6d7645c25041"},{"fixed":"12bf3e0182ccdaf3b412756a756d3944a7dacaa9"},{"fixed":"4e01022974355732e748ec8ebc97c558cb624ffe"},{"fixed":"cda4aacfb0bbf5c0f90fd0b42c72c749635d1368"},{"fixed":"eb476289c12cc22c8766f8a84eeb7ab46c4e8fb6"},{"fixed":"fd22370226a0d8109045d0831fd5aaadee921693"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89784.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.2.0"},{"fixed":"5.10.270"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.221"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.188"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.157"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.110"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.52"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89784.json"}}],"schema_version":"1.9.0"}