An integer overflow in the qla2x00_sysfs_write_optrom_ctl function in drivers/scsi/qla2xxx/qla_attr.c in the Linux kernel through 4.12.10 allows local users to cause a denial of service (memory corruption and system crash) by leveraging root access.
https://usn.ubuntu.com/3583-2/
https://usn.ubuntu.com/3583-1/
https://patchwork.kernel.org/patch/9929625/
https://lists.debian.org/debian-lts-announce/2017/12/msg00004.html