CVE-2025-21640
Description
In the Linux kernel, the following vulnerability has been resolved: sctp: sysctl: cookie_hmac_alg: 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.sctp_hmac_alg' 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/03ca51faba2b017bf6c90e139434c4117d0afcdc
- https://git.kernel.org/stable/c/3cd0659deb9c03535fd61839e91d4d4d3e51ac71
- https://git.kernel.org/stable/c/5599b212d2f4466e1832a94e9932684aaa364587
- https://git.kernel.org/stable/c/86ddf8118123cb58a0fb8724cad6979c4069065b
- https://git.kernel.org/stable/c/ad673e514b2793b8d5902f6ba6ab7e890dea23d5
- https://git.kernel.org/stable/c/ea62dd1383913b5999f3d16ae99d411f41b528d4
- https://git.kernel.org/stable/c/f0bb3935470684306e4e04793a20ac4c4b08de0b
- 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-2025-21640.html
- https://security-tracker.debian.org/tracker/CVE-2025-21640
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.