CVE-2026-89664

In the Linux kernel, the following vulnerability has been resolved: nfsd: release OPEN-decoded posix ACLs via op_release nfsd4_decode_createhow4() calls nfsd4_decode_fattr4(), which allocates refcounted struct posix_acl objects via posix_acl_alloc() and stores them in open->op_pacl and open->op_dpacl. These pointers must be released once the OPEN compound finishes. When nfsd4_decode_open_claim4() returns a non-seqid-mutating error, the dispatcher short-circuits before op_func runs: nfsd4_proc_compound() if (op->status && op->opnum == OP_OPEN) op->status = nfsd4_open_omfg(...) if (!seqid_mutating_err(ntohl(op->status))) return op->status; /* nfsd4_open() never runs */ ... opdesc->op_release(&op->u) /* must still release op_pacl/op_dpacl */ Before this change OP_OPEN had no .op_release in nfsd4_ops[], and the release pair lived inside nfsd4_open() at its out_err: label. On the short-circuit path nfsd4_open() is never invoked, so both posix_acl refs leak on every malformed OPEN compound that carries valid POSIX ACL createhow4 attributes. Add nfsd4_open_release() and wire it as .op_release for OP_OPEN. posix_acl_release() is NULL-safe, so the single release site covers both the normal path and the nfsd4_open_omfg short-circuit. Remove the matching posix_acl_release() pair from nfsd4_open()'s out_err: label to avoid double-releasing. The compound loop has two encoding branches: nfsd4_encode_operation() for normal ops, and nfsd4_encode_replay() for v4.0 replayed ops. op_release was only called from nfsd4_encode_operation(), so resources attached to op->u leak on the replay path. Move the op_release() call out of nfsd4_encode_operation() and the replay branch, placing it after the if-else in nfsd4_proc_compound(). This gives a single call site in a fairly obviously-correct place, covering both the normal encoding and replay paths.

• https://git.kernel.org/stable/c/5b3a7d7c23c071efe12dd1bc1d2e5f97c4892921
• https://git.kernel.org/stable/c/8215892993ea9f5231da4fa9eb42428a286fce8b

Published

Sep 11, 2026

Last Modified

Sep 13, 2026

Status

Received

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2026-89659In the Linux kernel, the following vulnerability has been re…9.8
• CVE-2026-8966Information disclosure in the IP Protection component. This …7.5
• CVE-2026-89660In the Linux kernel, the following vulnerability has been re…9.8
• CVE-2026-89661In the Linux kernel, the following vulnerability has been re…
• CVE-2026-89662In the Linux kernel, the following vulnerability has been re…9.8
• CVE-2026-89663In the Linux kernel, the following vulnerability has been re…8.8
• CVE-2026-89665In the Linux kernel, the following vulnerability has been re…8.2
• CVE-2026-89666In the Linux kernel, the following vulnerability has been re…
• CVE-2026-89667In the Linux kernel, the following vulnerability has been re…8.1
• CVE-2026-89668In the Linux kernel, the following vulnerability has been re…7.8
• CVE-2026-89669In the Linux kernel, the following vulnerability has been re…9.8
• CVE-2026-8967Information disclosure in the Graphics: WebGPU component. Th…7.5