CVE-2025-39847
Description
In the Linux kernel, the following vulnerability has been resolved: ppp: fix memory leak in pad_compress_skb If alloc_skb() fails in pad_compress_skb(), it returns NULL without releasing the old skb. The caller does: skb = pad_compress_skb(ppp, skb); if (!skb) goto drop; drop: kfree_skb(skb); When pad_compress_skb() returns NULL, the reference to the old skb is lost and kfree_skb(skb) ends up doing nothing, leading to a memory leak. Align pad_compress_skb() semantics with realloc(): only free the old skb if allocation and compression succeed. At the call site, use the new_skb variable so the original skb is not lost when pad_compress_skb() fails.
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 | 6.17 | affected | |
| debian | 11.0 | affected | |
References
- https://git.kernel.org/stable/c/0b21e9cd4559102da798bdcba453b64ecd7be7ee
- https://git.kernel.org/stable/c/1d8b354eafb8876d8bdb1bef69c7d2438aacfbe8
- https://git.kernel.org/stable/c/33a5bac5f14772730d2caf632ae97b6c2ee95044
- https://git.kernel.org/stable/c/4844123fe0b853a4982c02666cb3fd863d701d50
- https://git.kernel.org/stable/c/631fc8ab5beb9e0ec8651fb9875b9a968e7b4ae4
- https://git.kernel.org/stable/c/85c1c86a67e09143aa464e9bf09c397816772348
- https://git.kernel.org/stable/c/87a35a36742df328d0badf4fbc2e56061c15846c
- https://git.kernel.org/stable/c/9ca6a040f76c0b149293e430dabab446f3fc8ab7
- 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-2025-39847.html
- https://security-tracker.debian.org/tracker/CVE-2025-39847
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.