nfsd: size fh_verify server sockaddr slot by xpt_locallen
Summary
| CVE | CVE-2026-89702 |
|---|
| State | PUBLISHED |
|---|
| Assigner | Linux |
|---|
| Source Priority | CVE Program / NVD first with legacy fallback |
|---|
| Published | 2026-09-11 20:19:57 UTC |
|---|
| Updated | 2026-09-11 20:19:57 UTC |
|---|
| Description | In the Linux kernel, the following vulnerability has been resolved:
nfsd: size fh_verify server sockaddr slot by xpt_locallen
The nfsd_fh_verify and nfsd_fh_verify_err tracepoints declare the
server sockaddr slot sized by xpt_remotelen but fill it from
xpt_local using xpt_locallen:
TP_STRUCT__entry(
...
__sockaddr(server, rqstp->rq_xprt->xpt_remotelen)
...
)
TP_fast_assign(
...
__assign_sockaddr(server, &rqstp->rq_xprt->xpt_local,
rqstp->rq_xprt->xpt_locallen);
...
)
When xpt_locallen exceeds xpt_remotelen, __assign_sockaddr's memcpy
writes past the reserved ring-buffer slot. In the reverse direction
(xpt_locallen < xpt_remotelen) the slot is oversized and the
unwritten tail leaks prior ring-buffer contents to trace consumers.
The write-past-end case is reachable on NFS/UDP. svc_xprt_set_remote()
is only called from svc_tcp_accept() (net/sunrpc/svcsock.c) and from
the RDMA connect path; svc_create_socket() for UDP calls only
svc_xprt_set_local(), so xpt_remotelen stays 0 for the xprt's
lifetime. Every fh_verify trace for an NFSv2/v3-over-UDP request
then copies 16 or 28 bytes from xpt_local into a zero-byte slot.
The other NFSD tracepoints that record the server address
(NFSD_TRACE_PROC_CALL_FIELDS, NFSD_TRACE_PROC_RES_FIELDS,
SVC_RQST_ENDPOINT_FIELDS) already size the server slot by
xpt_locallen; nfsd_fh_verify and nfsd_fh_verify_err were the only
exceptions.
Fix by sizing the server slot with xpt_locallen so the declared slot
matches the copy length. The client slot and its assignment already
agree on xpt_remotelen and are left untouched. |
|---|
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|
| CNA |
Linux |
Linux |
affected 051382885552e12541cc0ebf82092be374a9ed2a 95d064f9828a20ccca5ae90a17be3e2076f25272 git |
Not specified |
| CNA |
Linux |
Linux |
affected 051382885552e12541cc0ebf82092be374a9ed2a 7ff8d6363cffff45654ea85e319f7c0c54226012 git |
Not specified |
| CNA |
Linux |
Linux |
affected 051382885552e12541cc0ebf82092be374a9ed2a 719a10e3f5f868c3c4ac3cf3648c5775d12034bd git |
Not specified |
| CNA |
Linux |
Linux |
affected 051382885552e12541cc0ebf82092be374a9ed2a 71d068490098b1d23c63b2345e40675d3a1ca763 git |
Not specified |
| CNA |
Linux |
Linux |
affected dcbebc86850324fbe0a993ce352f0539cd98038a git |
Not specified |
| CNA |
Linux |
Linux |
affected 62980365d6e894234b29f44fb2bfad4f7f8bb824 git |
Not specified |
| CNA |
Linux |
Linux |
affected 5.15.154 5.16 semver |
Not specified |
| CNA |
Linux |
Linux |
affected 6.0 |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.0 semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.12.109 6.12.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.18.50 6.18.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.2.4 7.2.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.3-rc1 * original_commit_for_fix |
Not specified |
References
| Reference | Source | Link | Tags |
|---|
| git.kernel.org/stable/c/7ff8d6363cffff45654ea85e319f7c0c54226012 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/95d064f9828a20ccca5ae90a17be3e2076f25272 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/71d068490098b1d23c63b2345e40675d3a1ca763 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/719a10e3f5f868c3c4ac3cf3648c5775d12034bd |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| CVE Program record |
CVE.ORG |
www.cve.org |
canonical |
| NVD vulnerability detail |
NVD |
nvd.nist.gov |
canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.