CVE-2025-21639
Description
In the Linux kernel, the following vulnerability has been resolved: sctp: sysctl: rto_min/max: avoid using current->nsproxy As mentioned in a previous commit of this series, using the 'net' structure via 'current' is not recommended for different reasons: - Inconsistency: getting info from the reader's/writer's netns vs only from the opener's netns. - current->nsproxy can be NULL in some cases, resulting in an 'Oops' (null-ptr-deref), e.g. when the current task is exiting, as spotted by syzbot [1] using acct(2). The 'net' structure can be obtained from the table->data using container_of(). Note that table->data could also be used directly, as this is the only member needed from the 'net' structure, but that would increase the size of this fix, to use '*data' everywhere 'net->sctp.rto_min/max' is used.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| sles | affected | | |
| debian | bookworm | fixed | 6.1.128-1 |
| debian | bullseye | fixed | 5.10.234-1 |
| debian | forky | fixed | 6.12.10-1 |
| debian | sid | fixed | 6.12.10-1 |
| debian | trixie | fixed | 6.12.10-1 |
| linux-kernel | affected | 6.1.125 | |
| linux-kernel | 6.13 | affected | |
References
- https://git.kernel.org/stable/c/0f78f09466744589e420935e646ae78212a38290
- https://git.kernel.org/stable/c/246428bfb9e7db15c5cd08e1d0eca41b65af2b06
- https://git.kernel.org/stable/c/4059507e34aa5fe0fa9fd5b2b5f0c8b26ab2d482
- https://git.kernel.org/stable/c/9fc17b76fc70763780aa78b38fcf4742384044a5
- https://git.kernel.org/stable/c/c87f1f6ade56c711f8736901e330685b453e420e
- https://git.kernel.org/stable/c/c8d179f3b1c1d60bf4484f50aa67b4c70f91bff9
- https://git.kernel.org/stable/c/dc9d0e3cfd16f66fbf0862857c6b391c8613ca9f
- https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html
- https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html
- https://cert-portal.siemens.com/productcert/html/ssa-265688.html
- https://www.suse.com/security/cve/CVE-2025-21639.html
- https://security-tracker.debian.org/tracker/CVE-2025-21639
CWEs
CWE-476
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.