CVE-2017-12193
Description
A flaw was found in the Linux kernel's implementation of associative arrays introduced in 3.13. This functionality was backported to the 3.10 kernels in Red Hat Enterprise Linux 7. The flaw involved a null pointer dereference in assoc_array_apply_edit() due to incorrect node-splitting in assoc_array implementation. This affects the keyring key type and thus key addition and link creation operations may cause the kernel to panic.
Statement
This issue does not affect the Linux kernel packages as shipped with Red Hat Enterprise Linux 5 and 6.
This issue affects the Linux kernel packages as shipped with Red Hat Enterprise Linux 7,MRG-2 and realtime kernels. Future Linux kernel updates for the respective releases may 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 v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 4.7 | 5.5 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | High | Low | N/A |
| Privileges Required | Low | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart
NULL pointer dereferences usually result in the failure of the process unless exception handling (on some platforms) is available and implemented. Even when exception handling is being used, it can still be very difficult to return the software to a safe state of operation.
Integrity,Confidentiality
Technical Impact: Execute Unauthorized Code or Commands; Read Memory; Modify Memory
In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution.
Acknowledgements
Red Hat would like to thank Fan Wu (University of Hong Kong), Haoran Qiu (University of Hong Kong), Heming Cui (University of Hong Kong), and Shixiong Zhao (University of Hong Kong) for reporting this issue.
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