CVE-2025-39848
Description
In the Linux kernel, the following vulnerability has been resolved: ax25: properly unshare skbs in ax25_kiss_rcv() Bernard Pidoux reported a regression apparently caused by commit c353e8983e0d ("net: introduce per netns packet chains"). skb->dev becomes NULL and we crash in __netif_receive_skb_core(). Before above commit, different kind of bugs or corruptions could happen without a major crash. But the root cause is that ax25_kiss_rcv() can queue/mangle input skb without checking if this skb is shared or not. Many thanks to Bernard Pidoux for his help, diagnosis and tests. We had a similar issue years ago fixed with commit 7aaed57c5c28 ("phonet: properly unshare skbs in phonet_rcv()").
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 | 6.1.153-1 |
| debian | bullseye | fixed | 5.10.244-1 |
| debian | forky | fixed | 6.16.6-1 |
| debian | sid | fixed | 6.16.6-1 |
| debian | trixie | fixed | 6.12.48-1 |
| linux-kernel | affected | 5.4.299 | |
| linux-kernel | 2.6.12 | affected | |
| linux-kernel | 6.17 | affected | |
| debian | 11.0 | affected | |
References
- https://git.kernel.org/stable/c/01a2984cb803f2d487b7074f9718db2bf3531f69
- https://git.kernel.org/stable/c/2bd0f67212908243ce88e35bf69fa77155b47b14
- https://git.kernel.org/stable/c/42b46684e2c78ee052d8c2ee8d9c2089233c9094
- https://git.kernel.org/stable/c/5b079be1b9da49ad88fc304c874d4be7085f7883
- https://git.kernel.org/stable/c/7d449b7a6c8ee434d10a483feed7c5c50108cf56
- https://git.kernel.org/stable/c/8156210d36a43e76372312c87eb5ea3dbb405a85
- https://git.kernel.org/stable/c/89064cf534bea4bb28c83fe6bbb26657b19dd5fe
- https://git.kernel.org/stable/c/b1c71d674a308d2fbc83efcf88bfc4217a86aa17
- 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-032379.html
- https://www.suse.com/security/cve/CVE-2025-39848.html
- https://security-tracker.debian.org/tracker/CVE-2025-39848
CWEs
CWE-401
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.