{"id":"CVE-2026-53396","summary":"nfsd: fix posix_acl leak and ignored error in nfsd4_create_file","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix posix_acl leak and ignored error in nfsd4_create_file\n\nnfsd4_create_file() has two bugs in its ACL handling:\n\nThe return value of nfsd4_acl_to_attr() is silently discarded.  When\nthe NFSv4-to-POSIX ACL conversion fails (e.g., -EINVAL for\nunsupported ACE types), the file is created without any ACL and the\nclient receives NFS4_OK.  This violates RFC 7530/8881 which require\nthe server to reject unsupported attributes on CREATE.\n\nWhen start_creating() fails after ACL attributes have been populated\nin attrs (either via nfsd4_acl_to_attr or via ownership transfer from\nopen-\u003eop_dpacl/op_pacl), the function jumps to out_write which skips\nnfsd_attrs_free().  The posix_acl allocations are leaked.  A client\ncan trigger this repeatedly with OPEN(CREATE), ACL attributes, and an\ninvalid filename (e.g., longer than NAME_MAX).\n\nFix both by capturing the nfsd4_acl_to_attr() return value and by\nchanging the early error paths to jump to out instead of out_write.\nInitialize child to ERR_PTR(-EINVAL) so that end_creating() is safe\nto call even if start_creating() was never reached.","modified":"2026-07-23T09:59:47.043710190Z","published":"2026-07-19T12:01:58.375Z","related":["openSUSE-SU-2026:11339-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53396.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/18cf006a08babec0bbac2a3784f8f28e56e47490"},{"type":"WEB","url":"https://git.kernel.org/stable/c/24c975bbdd564d7d0ad90294bfa69729830345de"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53396.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53396"},{"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":"7ab96df840e60eb933abfe65fc5fe44e72f16dc0"},{"fixed":"18cf006a08babec0bbac2a3784f8f28e56e47490"},{"fixed":"24c975bbdd564d7d0ad90294bfa69729830345de"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53396.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.3"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53396.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H"}]}