In the Linux kernel, the following vulnerability has been resolved:
NFSD: Protect against send buffer overflow in NFSv3 READDIR
Since before the git era, NFSD has conserved the number of pages
held by each nfsd thread by combining the RPC receive and send
buffers into a single array of pages. This works because there are
no cases where an operation needs a large RPC Call message and a
large RPC Reply message at the same time.
Once an RPC Call has been received, svc_process() updates
svc_rqst::rq_res to describe the part of rq_pages that can be
used for constructing the Reply. This means that the send buffer
(rq_res) shrinks when the received RPC record containing the RPC
Call is large.
A client can force this shrinkage on TCP by sending a correctly-
formed RPC Call header contained in an RPC record that is
excessively large. The full maximum payload size cannot be
constructed in that case.
Thanks to Aleksi Illikainen and Kari Hulkko for uncovering this
issue.
NFSD: Protect against send buffer overflow in NFSv3 READDIR
Since before the git era, NFSD has conserved the number of pages
held by each nfsd thread by combining the RPC receive and send
buffers into a single array of pages. This works because there are
no cases where an operation needs a large RPC Call message and a
large RPC Reply message at the same time.
Once an RPC Call has been received, svc_process() updates
svc_rqst::rq_res to describe the part of rq_pages that can be
used for constructing the Reply. This means that the send buffer
(rq_res) shrinks when the received RPC record containing the RPC
Call is large.
A client can force this shrinkage on TCP by sending a correctly-
formed RPC Call header contained in an RPC record that is
excessively large. The full maximum payload size cannot be
constructed in that case.
Thanks to Aleksi Illikainen and Kari Hulkko for uncovering this
issue.
Metrics
Affected Vendors & Products
No data.
No data.
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Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Sat, 04 Oct 2025 15:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: NFSD: Protect against send buffer overflow in NFSv3 READDIR Since before the git era, NFSD has conserved the number of pages held by each nfsd thread by combining the RPC receive and send buffers into a single array of pages. This works because there are no cases where an operation needs a large RPC Call message and a large RPC Reply message at the same time. Once an RPC Call has been received, svc_process() updates svc_rqst::rq_res to describe the part of rq_pages that can be used for constructing the Reply. This means that the send buffer (rq_res) shrinks when the received RPC record containing the RPC Call is large. A client can force this shrinkage on TCP by sending a correctly- formed RPC Call header contained in an RPC record that is excessively large. The full maximum payload size cannot be constructed in that case. Thanks to Aleksi Illikainen and Kari Hulkko for uncovering this issue. | |
| Title | NFSD: Protect against send buffer overflow in NFSv3 READDIR | |
| References |
|
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-10-04T15:16:44.462Z
Reserved: 2025-10-04T15:13:33.468Z
Link: CVE-2022-50487
Vulnrichment
No data.
NVD
Status : Received
Published: 2025-10-04T16:15:45.590
Modified: 2025-10-04T16:15:45.590
Link: CVE-2022-50487
Redhat
No data.
OpenCVE Enrichment
No data.