Description
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.
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.
Published:
2026-09-11
Score:
n/a
EPSS:
n/a
KEV:
No
Impact:
n/a
Action:
n/a
Analysis
No analysis available yet.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
|||||||||||||||
| Linux | Linux | affected |
|
No data.
No data.
No data available yet.
Remediation
No remediation available yet.
Tracking
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Advisories
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References
History
Fri, 11 Sep 2026 23:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | nfsd: release OPEN-decoded posix ACLs via op_release | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-11T19:45:51.319Z
Reserved: 2026-09-11T19:38:34.745Z
Link: CVE-2026-89664
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-11T20:19:52.790
Modified: 2026-09-11T20:19:52.790
Link: CVE-2026-89664
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.