CVE-2024-50126
Description
A use-after-free vulnerability was found in the taprio_dump() function in the Linux kernel.
Statement
A use-after-free vulnerability was found in the Linux kernel's traffic control (tc) subsystem in the taprio_dump() function of the TAPRIO qdisc. When a TAPRIO qdisc was dumped or replaced through rtnetlink, taprio_dump() could read scheduling data that had already been freed because it was not executed inside an RCU read-side critical section. Exploiting this flaw requires local access and the ability to configure traffic-control qdiscs; the issue was detected with KASAN on an arm64 system. Red Hat Product Security has rated this flaw as Moderate impact. Although the CVSS 3.1 base score of 7.8 reflects the theoretical maximum impact of a local use-after-free, practical exploitation is limited by the need for local privileged access, and the observed manifestation is a small read of already-freed memory rather than demonstrated arbitrary code execution. Red Hat Enterprise Linux 9 is affected, and a fix is being pursued through the delegated kernel process for RHEL 9.6, while the RHEL 9.5.z maintenance stream has been marked as won't fix for this issue. Red Hat Enterprise Linux 6, 7, and 8, as well as Red Hat's hosted OpenShift offerings (ARO and OSD), are not affected. Fedora is affected, with its resolution handled by the community.
Mitigation
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
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 | 7.8 | 7.8 | 7.8 |
| Attack Vector | Local | Local | Local |
| Attack Complexity | Low | Low | Low |
| Privileges Required | Low | Low | Low |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | High | High | High |
| Integrity Impact | High | High | High |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Memory
The use of previously freed memory may corrupt valid data, if the memory area in question has been allocated and used properly elsewhere.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
If chunk consolidation occurs after the use of previously freed data, the process may crash when invalid data is used as chunk information.
Confidentiality
Technical Impact: Read Memory
Read operations on freed memory can sometimes leak sensitive information instead of causing a crash
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands
If malicious data is entered before chunk consolidation can take place, it may be possible to take advantage of a write-what-where primitive to execute arbitrary code. If the newly allocated data happens to hold a class, in C++ for example, various function pointers may be scattered within the heap data. If one of these function pointers is overwritten with an address to valid shellcode, execution of arbitrary code can be achieved.
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