Race condition in the store_int_with_restart() function in arch/x86/kernel/cpu/mcheck/mce.c in the Linux kernel allows local users to cause a denial of service (panic) by leveraging root access to write to the check_interval file in a /sys/devices/system/machinecheck/machinecheck<cpu number> directory. References: https://lkml.org/lkml/2018/3/2/970 An upsteam patch: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b3b7c4795ccab5be71f080774c45bbbcc75c2aaf
Created kernel tracking bugs for this issue: Affects: fedora-all [bug 1553918]
kernel-4.15.9-200.fc26 has been pushed to the Fedora 26 stable repository. If problems still persist, please make note of it in this bug report.
Notes: Since only root can write to the mentioned sysfs variables, the issue is not a security flaw.