Vulnerability-Lookup

GHSA-X95X-W6HQ-MWXC

Vulnerability from github – Published: 2024-05-21 15:31 – Updated: 2026-05-12 12:31

Details

In the Linux kernel, the following vulnerability has been resolved:

nfsd: fix NULL dereference in nfs3svc_encode_getaclres

In error cases the dentry may be NULL.

Before 20798dfe249a, the encoder also checked dentry and d_really_is_positive(dentry), but that looks like overkill to me--zero status should be enough to guarantee a positive dentry.

This isn't the first time we've seen an error-case NULL dereference hidden in the initialization of a local variable in an xdr encoder. But I went back through the other recent rewrites and didn't spot any similar bugs.

Severity

5.5 (Medium)


                  
                    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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CVE-2021-47316 (GCVE-0-2021-47316)

Vulnerability from cvelistv5 – Published: 2024-05-21 14:35 – Updated: 2026-10-14 12:12

Title

nfsd: fix NULL dereference in nfs3svc_encode_getaclres

Summary

In the Linux kernel, the following vulnerability has been resolved: nfsd: fix NULL dereference in nfs3svc_encode_getaclres In error cases the dentry may be NULL. Before 20798dfe249a, the encoder also checked dentry and d_really_is_positive(dentry), but that looks like overkill to me--zero status should be enough to guarantee a positive dentry. This isn't the first time we've seen an error-case NULL dereference hidden in the initialization of a local variable in an xdr encoder. But I went back through the other recent rewrites and didn't spot any similar bugs.

Severity

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2024-05-21 18:45 UTC

Assigner

Linux CNA under the mitre root

CNA scorecard D 53/100 over 6637 records in the last 180 days details

References

5 references

URL	Tags
https://git.kernel.org/stable/c/e79057d15d96ef19d…
https://git.kernel.org/stable/c/650e6f383a6eb40f7…
https://git.kernel.org/stable/c/ab1016d39cc052064…
https://cert-portal.siemens.com/productcert/html/…
https://cert-portal.siemens.com/productcert/html/…

Impacted products

3 products

Vendor	Product	Version
Linux	Linux	Affected: d505e66191072748620fc0af038cea4e4da0e3cd , < e79057d15d96ef19de4de6d7e479bae3d58a2a8d (git) Affected: 20798dfe249a01ad1b12eec7dbc572db5003244a , < 650e6f383a6eb40f7c0a010982a74ab4b6893870 (git) Affected: 20798dfe249a01ad1b12eec7dbc572db5003244a , < ab1016d39cc052064e32f25ad18ef8767a0ee3b8 (git)
Linux	Linux	Affected: 5.13 Unaffected: 0 , < 5.13 (semver) Unaffected: 5.13.4 , ≤ 5.13.* (semver) Unaffected: 5.14 , ≤ * (original_commit_for_fix)
Siemens	SIMATIC S7-1500 TM MFP - GNU/Linux subsystem	Affected: 0 , < V1.1.1 (custom)

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JSON

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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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