It was found that in Linux kernel the mount table expands by a power-of-two with each bind mount command. If a system is configured to allow non-privileged user to do bind mounts, or allows to do so in a container or unprivileged mount namespace, then non-privileged user is able to cause a local DoS by overflowing the mount table, which causes a deadlock for the whole system.
Find out more about CVE-2016-6213 from the MITRE CVE dictionary dictionary and NIST NVD.
This issue does not affect the Linux kernel packages as shipped with Red Hat Enterprise Linux 5, 6, 7 and MRG-2 as of now due to the absence of unprivileged mount name spaces support.
Nevertheless, the unprivileged mount name spaces might be added to a future RHEL-7 version as a supported feature, so future Linux kernel updates for the respective releases might address this issue.
| Base Score | 4 |
|---|---|
| Base Metrics | AV:L/AC:H/Au:N/C:N/I:N/A:C |
| Access Vector | Local |
| Access Complexity | High |
| Authentication | None |
| Confidentiality Impact | None |
| Integrity Impact | None |
| Availability Impact | Complete |
| CVSS3 Base Score | 4.7 |
|---|---|
| CVSS3 Base Metrics | CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H |
| Attack Vector | Local |
| Attack Complexity | High |
| Privileges Required | Low |
| User Interaction | None |
| Scope | Unchanged |
| Confidentiality | None |
| Integrity Impact | None |
| Availability Impact | High |
Find out more about Red Hat support for the Common Vulnerability Scoring System (CVSS).
| Platform | Errata | Release Date |
|---|---|---|
| Red Hat Enterprise Linux 7 (kernel) | RHSA-2017:1842 | 2017-08-01 |
| Red Hat Enterprise Linux for Real Time for NFV (v. 7) (kernel-rt) | RHSA-2017:2077 | 2017-08-01 |
| Platform | Package | State |
|---|---|---|
| Red Hat Enterprise MRG 2 | realtime-kernel | Not affected |
| Red Hat Enterprise Linux 6 | kernel | Not affected |
| Red Hat Enterprise Linux 5 | kernel | Not affected |
Vulmon