In the Linux kernel, the following vulnerability has been resolved:
net/sched: cake: reject overhead values that underflow length
CAKE accepts signed overhead values and stores them in an s16, but the adjusted packet length calculation uses unsigned arithmetic. A negative effective length can therefore wrap to a large value.
Such configurations make rate accounting depend on integer wraparound rather than on the packet size userspace intended to model. A static netlink lower bound is not enough because packets reaching CAKE can be smaller than any reasonable manual-overhead allowance.
Fold the signed overhead adjustment into the existing datapath MPU clamp so negative adjusted lengths are clamped before link-layer framing adjustments.
References
- https://git.kernel.org/stable/c/297f459865360b46a887667cbf3aac6a6f013841
- https://git.kernel.org/stable/c/336c1e414fc0e9844d445174e8ada2a7dd8d1c4b
- https://git.kernel.org/stable/c/7aa0e64fea778a9e3df73e64da95367ff8ad2ea5
- https://git.kernel.org/stable/c/b7f97cae7ec1b6c3c32843c42be218690d310467
- https://git.kernel.org/stable/c/bcdf3a3664f7d2c4e37e155f30f72ef33f041804
- https://git.kernel.org/stable/c/e1df6cff03aad8c96e55a8b2a991e505c7a3ff6f
- https://git.kernel.org/stable/c/f1e7807df5bf2d42a40266430e9f82f37633cdcf
- https://git.kernel.org/stable/c/f511dd7bf6077aa7afbe72914520553fedaacbb4