Medium · published May 27, 2026
In the Linux kernel, the following vulnerability has been resolved:
netfilter: reject zero shift in nft_bitwise
Reject zero shift operands for nft_bitwise left and right shift
expressions during initialization.
The carry propagation logic computes the carry from the adjacent 32-bit
word using BITS_PER_TYPE(u32) - shift. A zero shift operand turns this
into a 32-bit shift, which is undefined behaviour.
Reject zero shift operands in the control plane, alongside the existing
check for values greater than or equal to 32, so malformed rules never
reach the packet path.
| Product | Versions | Fixed in |
|---|---|---|
| linux/linux_kernel | ≥ 5.6, < 5.10.258 | 5.10.258 |
| linux/linux_kernel | ≥ 5.11, < 5.15.209 | 5.15.209 |
| linux/linux_kernel | ≥ 5.16, < 6.1.175 | 6.1.175 |
| linux/linux_kernel | ≥ 6.2, < 6.6.140 | 6.6.140 |
| linux/linux_kernel | ≥ 6.7, < 6.12.86 | 6.12.86 |
| linux/linux_kernel | ≥ 6.13, < 6.18.27 | 6.18.27 |
| linux/linux_kernel | ≥ 6.19, < 7.0.4 | 7.0.4 |
| linux/linux_kernel | all versions | — |