CVE-2024-35982
Description
In the Linux kernel, the following vulnerability has been resolved: batman-adv: Avoid infinite loop trying to resize local TT If the MTU of one of an attached interface becomes too small to transmit the local translation table then it must be resized to fit inside all fragments (when enabled) or a single packet. But if the MTU becomes too low to transmit even the header + the VLAN specific part then the resizing of the local TT will never succeed. This can for example happen when the usable space is 110 bytes and 11 VLANs are on top of batman-adv. In this case, at least 116 byte would be needed. There will just be an endless spam of batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (110) in the log but the function will never finish. Problem here is that the timeout will be halved all the time and will then stagnate at 0 and therefore never be able to reduce the table even more. There are other scenarios possible with a similar result. The number of BATADV_TT_CLIENT_NOPURGE entries in the local TT can for example be too high to fit inside a packet. Such a scenario can therefore happen also with only a single VLAN + 7 non-purgable addresses - requiring at least 120 bytes. While this should be handled proactively when: * interface with too low MTU is added * VLAN is added * non-purgeable local mac is added * MTU of an attached interface is reduced * fragmentation setting gets disabled (which most likely requires dropping attached interfaces) not all of these scenarios can be prevented because batman-adv is only consuming events without the the possibility to prevent these actions (non-purgable MAC address added, MTU of an attached interface is reduced). It is therefore necessary to also make sure that the code is able to handle also the situations when there were already incompatible system configuration are present.
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 | 6.1.90-1 |
| debian | bullseye | fixed | 5.10.216-1 |
| debian | forky | fixed | 6.8.9-1 |
| debian | sid | fixed | 6.8.9-1 |
| debian | trixie | fixed | 6.8.9-1 |
| linux-kernel | affected | 4.19.313 |
References
- https://git.kernel.org/stable/c/04720ea2e6c64459a90ca28570ea78335eccd924
- https://git.kernel.org/stable/c/3fe79b2c83461edbbf86ed8a6f3924820ff89259
- https://git.kernel.org/stable/c/4ca2a5fb54ea2cc43edea614207fcede562d91c2
- https://git.kernel.org/stable/c/70a8be9dc2fb65d67f8c1e0c88c587e08e2e575d
- https://git.kernel.org/stable/c/87b6af1a7683e021710c08fc0551fc078346032f
- https://git.kernel.org/stable/c/b1f532a3b1e6d2e5559c7ace49322922637a28aa
- https://git.kernel.org/stable/c/b3ddf6904073990492454b1dd1c10a24be8c74c6
- https://git.kernel.org/stable/c/ca54e2671548616ad34885f90d4f26f7adb088f0
- https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html
- https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html
- https://cert-portal.siemens.com/productcert/html/ssa-265688.html
- https://www.suse.com/security/cve/CVE-2024-35982.html
- https://security-tracker.debian.org/tracker/CVE-2024-35982
CWEs
CWE-835
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.