A security flaw was found in the Linux kernel's networking subsystem that destroying the network interface with huge number of ipv4 addresses assigned keeps "rtnl_lock" spinlock for a very long time (up to hour). This blocks many network-related operations, including creation of new incoming ssh connections. The problem is especially important for containers, as the container owner has enough permissions to trigger this and block a network access on a whole host, outside the container.
Find out more about CVE-2016-3156 from the MITRE CVE dictionary dictionary and NIST NVD.
This issue affects the Linux kernel packages as shipped with Red Hat Enterprise Linux 5, 6. This has been rated as having Moderate security impact and is not currently planned to be addressed in future updates, as the Linux containers which the flaw affects are not supported in these products. For additional information, refer to the Red Hat Enterprise Linux Life Cycle: https://access.redhat.com/support/policy/updates/errata/.
This issue affects the Linux kernel packages as shipped with Red Hat Enterprise Linux 7 and MRG-2. Future Linux kernel updates for the respective releases might address this issue.
| Base Score | 1.7 |
|---|---|
| Base Metrics | AV:L/AC:L/Au:S/C:N/I:N/A:P |
| Access Vector | Local |
| Access Complexity | Low |
| Authentication | Single |
| Confidentiality Impact | None |
| Integrity Impact | None |
| Availability Impact | Partial |
Find out more about Red Hat support for the Common Vulnerability Scoring System (CVSS).
| Platform | Errata | Release Date |
|---|---|---|
| Red Hat Enterprise Linux for Real Time for NFV (v. 7) (kernel-rt) | RHSA-2016:2584 | 2016-11-03 |
| Red Hat Enterprise Linux 7 (kernel) | RHSA-2016:2574 | 2016-11-03 |
| Platform | Package | State |
|---|---|---|
| Red Hat Enterprise MRG 2 | realtime-kernel | Will not fix |
| Red Hat Enterprise Linux 6 | kernel | Will not fix |
| Red Hat Enterprise Linux 5 | kernel | Will not fix |
Vulmon