Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: nftables: exthdr: fix 4-byte stack OOB write If priv->len is a multiple of 4, then dst[len / 4] can write past the destination array which leads to stack corruption. This construct is necessary to clean the remainder of the register in case ->len is NOT a multiple of the register size, so make it conditional just like nft_payload.c does. The bug was added in 4.1 cycle and then copied/inherited when tcp/sctp and ip option support was added. Bug reported by Zero Day Initiative project (ZDI-CAN-21950, ZDI-CAN-21951, ZDI-CAN-21961).
References
https://git.kernel.org/stable/c/a7d86a77c33ba1c357a7504341172cc1507f0698
https://git.kernel.org/stable/c/1ad7b189cc1411048434e8595ffcbe7873b71082
https://git.kernel.org/stable/c/d9ebfc0f21377690837ebbd119e679243e0099cc
https://git.kernel.org/stable/c/c8f292322ff16b9a2272a67de396c09a50e09dce
https://git.kernel.org/stable/c/fd94d9dadee58e09b49075240fe83423eb1dcd36
