CVE-2024-56659

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

net: lapb: increase LAPB_HEADER_LEN

It is unclear if net/lapb code is supposed to be ready for 8021q.

We can at least avoid crashes like the following :

skbuff: skb_under_panic: text:ffffffff8aabe1f6 len:24 put:20 head:ffff88802824a400 data:ffff88802824a3fe tail:0x16 end:0x140 dev:nr0.2

------------[ cut here ]------------

kernel BUG at net/core/skbuff.c:206 !

Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI

CPU: 1 UID: 0 PID: 5508 Comm: dhcpcd Not tainted 6.12.0-rc7-syzkaller-00144-g66418447d27b #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024

RIP: 0010:skb_panic net/core/skbuff.c:206 [inline]

RIP: 0010:skb_under_panic+0x14b/0x150 net/core/skbuff.c:216

Code: 0d 8d 48 c7 c6 2e 9e 29 8e 48 8b 54 24 08 8b 0c 24 44 8b 44 24 04 4d 89 e9 50 41 54 41 57 41 56 e8 1a 6f 37 02 48 83 c4 20 90 <0f> 0b 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3

RSP: 0018:ffff

/// 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