CVE-2024-35982

/// Technical 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 n

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References