CVE-2016-3156
Description
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.
Statement
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.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v2 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 1.7 | 2.1 | N/A |
| Attack Vector | Local | Local | N/A |
| Access Complexity | Low | Low | N/A |
| Authentication | Single | None | N/A |
| Confidentiality Impact | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | Partial | Partial | N/A |
Vector
Red Hat: AV:L/AC:L/Au:S/C:N/I:N/A:P
NVD: AV:L/AC:L/Au:N/C:N/I:N/A:P
Acknowledgements
Red Hat would like to thank Solar Designer (Openwall) and the Virtuozzo kernel team for reporting this issue.
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