Integer overflow in the envwrite function in the Alcatel-Lucent Bell Labs Plan 9 kernel allows local users to overwrite certain memory addresses with kernel…

Integer overflow in the envwrite function in the Alcatel-Lucent Bell Labs Plan 9 kernel allows local users to overwrite certain memory addresses with kernel memory via a large n argument, as demonstrated by (1) modifying the iseve function to gain privileges and (2) making the devpermcheck function grant unrestricted device permissions.