An issue was discovered in the Linux kernel through 4.17.3. An Integer Overflow in kernel/time/posix-timers.c in the POSIX timer code is caused by the way the overrun accounting works. Depending on interval and expiry time values, the overrun can be larger than INT_MAX, but the accounting is int based. This basically makes the accounting values, which are visible to user space via timer_getoverrun(2) and siginfo::si_overrun, random. For example, a local user can cause a denial of service (signed integer overflow) via crafted mmap, futex, timer_create, and timer_settime system calls.
NOTE: The following CVSS v3.0 metrics and score provided are preliminary and subject to review.
|Base Score:||5.5||Base Metrics:||AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H|
|Access Vector:||Local network||Attack Complexity:||Low|
|Privileges Required:||Low||User Interaction:||None|
|Integrity Impact:||None||Availability Impact:||High|
|Oracle Linux version 7 (kernel-uek)||ELSA-2018-4242||2018-10-10|
This page is generated automatically and has not been checked for errors or omissions. For clarification or corrections please contact the Oracle Linux ULN team