published August 15, 2026
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.