kernel/sched/fair.c in the Linux kernel before 5.3.9, when cpu.cfs_quota_us is used (e.g., with Kubernetes), allows attackers to cause a denial of service against non-cpu-bound applications by generating a workload that triggers unwanted slice expiration, aka CID-de53fd7aedb1. (In other words, although this slice expiration would typically be seen with benign workloads, it is possible that an attacker could calculate how many stray requests are required to force an entire Kubernetes cluster into a low-performance state caused by slice expiration, and ensure that a DDoS attack sent that number of stray requests. An attack does not affect the stability of the kernel; it only causes mismanagement of application execution.)
The product does not properly control the allocation and maintenance of a limited resource.
| Link | Tags |
|---|---|
| https://usn.ubuntu.com/4226-1/ | third party advisory vendor advisory |
| https://lists.debian.org/debian-lts-announce/2020/01/msg00013.html | third party advisory mailing list |
| https://www.oracle.com/security-alerts/cpuApr2021.html | third party advisory patch |
| https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.3.9 | patch vendor advisory mailing list |
| https://github.com/torvalds/linux/commit/de53fd7aedb100f03e5d2231cfce0e4993282425 | third party advisory patch |
| https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=de53fd7aedb100f03e5d2231cfce0e4993282425 | patch vendor advisory mailing list |
| https://relistan.com/the-kernel-may-be-slowing-down-your-app | third party advisory exploit |
| https://github.com/kubernetes/kubernetes/issues/67577 | patch third party advisory issue tracking |
| https://security.netapp.com/advisory/ntap-20200204-0002/ | third party advisory |