The replace_map_fd_with_map_ptr function in kernel/bpf/verifier.c in the Linux kernel before 4.5.5 does not properly maintain an fd data structure, which allows local users to gain privileges or cause a denial of service (use-after-free) via crafted BPF instructions that reference an incorrect file descriptor.
The MITRE CVE dictionary describes this issue as:
Find out more about CVE-2016-4557 from the MITRE CVE dictionary dictionary and NIST NVD.
This issue does not affect the Linux kernels as shipped with Red Hat Enterprise Linux 5, 6, 7 and Red Hat Enterprise MRG 2.
NOTE: The following CVSS v2 metrics and score provided are preliminary and subject to review.
| Base Score | 6.9 |
|---|---|
| Base Metrics | AV:L/AC:M/Au:N/C:C/I:C/A:C |
| Access Vector | Local |
| Access Complexity | Medium |
| Authentication | None |
| Confidentiality Impact | Complete |
| Integrity Impact | Complete |
| Availability Impact | Complete |
Find out more about Red Hat support for the Common Vulnerability Scoring System (CVSS).
| Platform | Package | State |
|---|---|---|
| Red Hat Enterprise MRG 2 | realtime-kernel | Not affected |
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected |
| Red Hat Enterprise Linux 7 | kernel | Not affected |
| Red Hat Enterprise Linux 6 | kernel | Not affected |
| Red Hat Enterprise Linux 5 | kernel | Not affected |
Vulmon