CVE-2025-38067
Description
In the Linux kernel, the following vulnerability has been resolved: rseq: Fix segfault on registration when rseq_cs is non-zero The rseq_cs field is documented as being set to 0 by user-space prior to registration, however this is not currently enforced by the kernel. This can result in a segfault on return to user-space if the value stored in the rseq_cs field doesn't point to a valid struct rseq_cs. The correct solution to this would be to fail the rseq registration when the rseq_cs field is non-zero. However, some older versions of glibc will reuse the rseq area of previous threads without clearing the rseq_cs field and will also terminate the process if the rseq registration fails in a secondary thread. This wasn't caught in testing because in this case the leftover rseq_cs does point to a valid struct rseq_cs. What we can do is clear the rseq_cs field on registration when it's non-zero which will prevent segfaults on registration and won't break the glibc versions that reuse rseq areas on thread creation.
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 | 6.1.147-1 |
| debian | bullseye | fixed | 5.10.244-1 |
| debian | forky | fixed | 6.16.3-1 |
| debian | sid | fixed | 6.16.3-1 |
| debian | trixie | fixed | 6.12.41-1 |
| linux-kernel | affected | 5.10.240 | |
| debian | 11.0 | affected | |
References
- https://git.kernel.org/stable/c/2df285dab00fa03a3ef939b6cb0d0d0aeb0791db
- https://git.kernel.org/stable/c/3e4028ef31b69286c9d4878cee0330235f53f218
- https://git.kernel.org/stable/c/48900d839a3454050fd5822e34be8d54c4ec9b86
- https://git.kernel.org/stable/c/b2b05d0dc2f4f0646922068af435aed5763d16ba
- https://git.kernel.org/stable/c/eaf112069a904b6207b4106ff083e0208232a2eb
- https://git.kernel.org/stable/c/f004f58d18a2d3dc761cf973ad27b4a5997bd876
- https://git.kernel.org/stable/c/fd881d0a085fc54354414aed990ccf05f282ba53
- https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html
- https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html
- https://www.suse.com/security/cve/CVE-2025-38067.html
- https://security-tracker.debian.org/tracker/CVE-2025-38067
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.