CVE-2026-53396

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> nfsd: fix posix_acl leak and ignored error in nfsd4_create_file<br /> <br /> nfsd4_create_file() has two bugs in its ACL handling:<br /> <br /> The return value of nfsd4_acl_to_attr() is silently discarded. When<br /> the NFSv4-to-POSIX ACL conversion fails (e.g., -EINVAL for<br /> unsupported ACE types), the file is created without any ACL and the<br /> client receives NFS4_OK. This violates RFC 7530/8881 which require<br /> the server to reject unsupported attributes on CREATE.<br /> <br /> When start_creating() fails after ACL attributes have been populated<br /> in attrs (either via nfsd4_acl_to_attr or via ownership transfer from<br /> open-&gt;op_dpacl/op_pacl), the function jumps to out_write which skips<br /> nfsd_attrs_free(). The posix_acl allocations are leaked. A client<br /> can trigger this repeatedly with OPEN(CREATE), ACL attributes, and an<br /> invalid filename (e.g., longer than NAME_MAX).<br /> <br /> Fix both by capturing the nfsd4_acl_to_attr() return value and by<br /> changing the early error paths to jump to out instead of out_write.<br /> Initialize child to ERR_PTR(-EINVAL) so that end_creating() is safe<br /> to call even if start_creating() was never reached.