Bug 1792512 (CVE-2019-19922) - CVE-2019-19922 kernel: when cpu.cfs_quota_us is used allows attackers to cause a denial of service against non-cpu-bound applications
Summary: CVE-2019-19922 kernel: when cpu.cfs_quota_us is used allows attackers to caus...
Keywords:
Status: NEW
Alias: CVE-2019-19922
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1792513
Blocks: 1792514
TreeView+ depends on / blocked
 
Reported: 2020-01-17 19:16 UTC by Guilherme de Almeida Suckevicz
Modified: 2020-01-28 16:34 UTC (History)
44 users (show)

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Description Guilherme de Almeida Suckevicz 2020-01-17 19:16:55 UTC
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.)

Reference:
https://github.com/kubernetes/kubernetes/issues/67577

Reference and upstream commit:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=de53fd7aedb100f03e5d2231cfce0e4993282425

Comment 1 Guilherme de Almeida Suckevicz 2020-01-17 19:17:50 UTC
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1792513]

Comment 2 Justin M. Forbes 2020-01-20 18:41:26 UTC
This was fixed for Fedora with the 5.3.9 stable kernel update.


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