Description
In the Linux kernel, the following vulnerability has been resolved:
NFSv4.2: fix LAYOUTSTATS send buffer exhaustion
encode_layoutstats_maxsz budgets XDR_QUADLEN(PNFS_LAYOUTSTATS_MAXSIZE),
i.e. 256 bytes, for the layoutupdate4 body written by the layout driver.
The flexfiles record can exceed that.
ff_layout_encode_ff_layoutupdate() emits, per data server, a netaddr4,
an nfs_fh4, two ff_io_latency4, an nfstime4 and a bool. A data server
whose filehandle is NFS_MAXFHSIZE bytes long already accounts for 132 of
those bytes, and the two ff_io_latency4 at 64 bytes each, the nfstime4
and the bool add a further 144, so the body passes 256 bytes before the
netaddr4 is encoded at all. encode_layoutstats() additionally writes
the deviceid4 and the layoutupdate4 lou_type word, neither of which the
macro accounts for.
The filehandle and the address are both chosen by the server, through
LAYOUTGET and GETDEVICEINFO, so it can drive the encoder past the
end of the send buffer. xdr_reserve_space() returns NULL once that
happens, and the two ff_layout_encode_io_latency() calls run with
dss_info->mirror->lock held, so a NULL return there leaves the lock
permanently held.
Raise PNFS_LAYOUTSTATS_MAXSIZE to 384 so that the record fits inside the
reservation.
NFSv4.2: fix LAYOUTSTATS send buffer exhaustion
encode_layoutstats_maxsz budgets XDR_QUADLEN(PNFS_LAYOUTSTATS_MAXSIZE),
i.e. 256 bytes, for the layoutupdate4 body written by the layout driver.
The flexfiles record can exceed that.
ff_layout_encode_ff_layoutupdate() emits, per data server, a netaddr4,
an nfs_fh4, two ff_io_latency4, an nfstime4 and a bool. A data server
whose filehandle is NFS_MAXFHSIZE bytes long already accounts for 132 of
those bytes, and the two ff_io_latency4 at 64 bytes each, the nfstime4
and the bool add a further 144, so the body passes 256 bytes before the
netaddr4 is encoded at all. encode_layoutstats() additionally writes
the deviceid4 and the layoutupdate4 lou_type word, neither of which the
macro accounts for.
The filehandle and the address are both chosen by the server, through
LAYOUTGET and GETDEVICEINFO, so it can drive the encoder past the
end of the send buffer. xdr_reserve_space() returns NULL once that
happens, and the two ff_layout_encode_io_latency() calls run with
dss_info->mirror->lock held, so a NULL return there leaves the lock
permanently held.
Raise PNFS_LAYOUTSTATS_MAXSIZE to 384 so that the record fits inside the
reservation.
Published:
2026-09-17
Score:
n/a
EPSS:
n/a
KEV:
No
Impact:
n/a
Action:
n/a
Analysis
Analysis and contextual insights are available on OpenCVE Cloud.
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 |
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| Linux | Linux | affected |
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No data.
No data.
No data available yet.
Remediation
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
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Advisories
No advisories yet.
References
History
Thu, 17 Sep 2026 16:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: NFSv4.2: fix LAYOUTSTATS send buffer exhaustion encode_layoutstats_maxsz budgets XDR_QUADLEN(PNFS_LAYOUTSTATS_MAXSIZE), i.e. 256 bytes, for the layoutupdate4 body written by the layout driver. The flexfiles record can exceed that. ff_layout_encode_ff_layoutupdate() emits, per data server, a netaddr4, an nfs_fh4, two ff_io_latency4, an nfstime4 and a bool. A data server whose filehandle is NFS_MAXFHSIZE bytes long already accounts for 132 of those bytes, and the two ff_io_latency4 at 64 bytes each, the nfstime4 and the bool add a further 144, so the body passes 256 bytes before the netaddr4 is encoded at all. encode_layoutstats() additionally writes the deviceid4 and the layoutupdate4 lou_type word, neither of which the macro accounts for. The filehandle and the address are both chosen by the server, through LAYOUTGET and GETDEVICEINFO, so it can drive the encoder past the end of the send buffer. xdr_reserve_space() returns NULL once that happens, and the two ff_layout_encode_io_latency() calls run with dss_info->mirror->lock held, so a NULL return there leaves the lock permanently held. Raise PNFS_LAYOUTSTATS_MAXSIZE to 384 so that the record fits inside the reservation. | |
| Title | NFSv4.2: fix LAYOUTSTATS send buffer exhaustion | |
| 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: 2026-09-17T16:06:13.519Z
Reserved: 2026-09-11T19:38:34.786Z
Link: CVE-2026-90103
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-17T17:17:02.063
Modified: 2026-09-17T17:17:02.063
Link: CVE-2026-90103
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.