CVE-2025-38231: debian debian_linux NULL Pointer Dereference
Vulnerability summary
CVE-2025-38231 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in debian debian_linux. EPSS estimates a 0.18% chance of exploitation in the next 30 days, higher than 7.5% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 52 · Related 47Timeline
- 04-07-2025PublishedVulnerability first disclosed.
- 15-10-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: nfsd: Initialize ssc before laundromat_work to prevent NULL dereference In nfs4_state_start_net(), laundromat_work may access nfsd_ssc through nfs4_laundromat -> nfsd4_ssc_expire_umount. If nfsd_ssc isn't initialized, this can cause NULL pointer dereference. Normally the delayed start of laundromat_work allows sufficient time for nfsd_ssc initialization to complete. However, when the kernel waits too long for userspace responses (e.g. in nfs4_state_start_net -> nfsd4_end_grace -> nfsd4_record_grace_done -> nfsd4_cld_grace_done -> cld_pipe_upcall -> __cld_pipe_upcall -> wait_for_completion path), the delayed work may start before nfsd_ssc initialization finishes. Fix this by moving nfsd_ssc initialization before starting laundromat_work.
CVSS metrics
3 scores · 3 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.18%
Chance of exploitation in the next 30 days
Percentile
8%
Versus all other CVEs
30-day change
+0.03 pp
From 0.16% on 20-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Ubuntu134 products
- linux< 5.15.0-156.166 | < 6.8.0-100.100
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 5.15.0-1092.99 | < 6.8.0-1046.49
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Debian2 products
- linux< 6.1.147-1 | < 6.12.35-1
- debian_linuxEOL11.0
Linux2 products
- linux≥ a4bc287943f5695209ff36bdc89f17b48d68fae7, < deaeb74ae9318252829c59a84a7d2316fc335660 | ≥ f4e44b393389c77958f7c58bf4415032b4cda15b, < 0fccf5f01ed28725cc313a66ca1247eef911d55e | ≥ f4e44b393389c77958f7c58bf4415032b4cda15b, < a97668ec6d73dab237cd1c15efe012a10090a4ed | ≥ f4e44b393389c77958f7c58bf4415032b4cda15b, < 5060e1a5fef184bd11d298e3f0ee920d96a23236 | ≥ f4e44b393389c77958f7c58bf4415032b4cda15b, < d622c2ee6c08147ab8c9b9e37d93b6e95d3258e0 | ≥ f4e44b393389c77958f7c58bf4415032b4cda15b, < 83ac1ba8ca102ab5c0ed4351f8ac6e74ac4d5d64 | ≥ f4e44b393389c77958f7c58bf4415032b4cda15b, < b31da62889e6d610114d81dc7a6edbcaa503fcf8 | ≥ 5.10.220, < 5.10.239 | 5.14
- linux_kernel≥ 5.10.220, < 5.10.239 | ≥ 5.14, < 5.15.186 | ≥ 5.16, < 6.1.142 | ≥ 6.2, < 6.6.95 | ≥ 6.7, < 6.12.35 | ≥ 6.13, < 6.15.4
3 vendors · 138 products
