In the Linux kernel, the following vulnerability has been resolved: ipv6: Fix signed integer overflow in l2tp_ip6_sendmsg When len >= INT_MAX - transhdrlen, ulen = len + transhdrlen will be overflow. To fix, we can follow what udpv6 does and subtract the transhdrlen from the max.
https://git.kernel.org/stable/c/f638a84afef3dfe10554c51820c16e39a278c915
https://git.kernel.org/stable/c/b8879ca1fd7348b4d5db7db86dcb97f60c73d751
https://git.kernel.org/stable/c/6c4e3486d21173d60925ef52e512cae727b43d30
https://git.kernel.org/stable/c/2f42389d270f2304c8855b0b63498a5a4d0c053d
https://git.kernel.org/stable/c/2cf73c7cb6125083408d77f43d0e84d86aed0000
https://git.kernel.org/stable/c/27a37755ceb401111ded76810359d3adc4b268a1
https://git.kernel.org/stable/c/0e818d433fc2718fe4da044ffca7431812a7e04e
https://git.kernel.org/stable/c/034246122f5c5e2e2a0b9fe04e24517920e9beb1