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CVE-2021-47556 Null pointer dereference

Routine
Remediate Within 6 Months

CVE Information

Original CVE data

Published:
Updated:

In the Linux kernel, the following vulnerability has been resolved: ethtool: ioctl: fix potential NULL deref in ethtool_set_coalesce() ethtool_set_coalesce() now uses both the .get_coalesce() and .set_coalesce() callbacks. But the check for their availability is buggy, so changing the coalesce settings on a device where the driver provides only _one_ of the callbacks results in a NULL pointer dereference instead of an -EOPNOTSUPP. Fix the condition so that the availability of both callbacks is ensured. This also matches the netlink code. Note that reproducing this requires some effort - it only affects the legacy ioctl path, and needs a specific combination of driver options: - have .get_coalesce() and .coalesce_supported but no .set_coalesce(), or - have .set_coalesce() but no .get_coalesce(). Here eg. ethtool doesn't cause the crash as it first attempts to call ethtool_get_coalesce() and bails out on error.

CWE:
CVSS v2-
CVSS v3-
References
https://git.kernel.org/stable/c/abfdd9e2f0f9699015d72317f74154d3e53664e6
https://git.kernel.org/stable/c/0276af2176c78771da7f311621a25d7608045827
Affected Vendors

Basic Analysis

Common vulnerability metrics

Vulnerabilty type as detected by PRIOnengine

Null pointer dereference

CVSS Scores as calculated by PRIOnengine
CVSS v25
AV:N/AC:L/AU:N/C:N/I:N/A:P
CVSS v37.5
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
MITRE CWE Top 25

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Exploits

No exploit code is reported to exist.

Active Exploitation

Vulnerability is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. See the KEV Catalog

Social Network Activity

-

Threat Actor Activity

No sightings of the vulnerability within threat reports.

Cybersecurity Frameworks

How the vulnerability maps against various cybersecurity frameworks

T1499 - Endpoint Denial of Service
T1498 - Network Denial of Service
T1203 - Exploitation for Client Execution
T1059 - Command and Scripting Interpreter

Compliance Impact

How the submited vulnerability affects compliance

PCI DSS v3.2.1-6.5.5 - Improper Error Handling
PCI DSS v3.2.1-6.5.2 - Buffer Overflows

Web Application Security Frameworks

Applicable if the issue likely affects a web application

WASC-19 - SQL Injection