CVE-2021-46994: linux kernel Null Dereference — Fix

Description

In the Linux kernel, the following vulnerability has been resolved: can: mcp251x: fix resume from sleep before interface was brought up Since 8ce8c0abcba3 the driver queues work via priv->restart_work when resuming after suspend, even when the interface was not previously enabled. This causes a null dereference error as the workqueue is only allocated and initialized in mcp251x_open(). To fix this we move the workqueue init to mcp251x_can_probe() as there is no reason to do it later and repeat it whenever mcp251x_open() is called. [mkl: fix error handling in mcp251x_stop()]

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CVSS v3.1 Score

5.5

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-476 CWE-476

Affected Products

Vendor	Product	Versions
linux	linux_kernel	5.5 — 5.10.38
linux	linux_kernel	5.11 — 5.11.22
linux	linux_kernel	5.12 — 5.12.5

References

Advisories & Patches

https://git.kernel.org/stable/c/03c427147b2d3e503af258711af4fc792b89b0af https://git.kernel.org/stable/c/6f8f1c27b577de15f69fefce3c502bb6300d825c https://git.kernel.org/stable/c/e1e10a390fd9479209c4d834d916ca5e6d5d396b https://git.kernel.org/stable/c/eecb4df8ec9f896b19ee05bfa632ac6c1dcd8f21 https://git.kernel.org/stable/c/03c427147b2d3e503af258711af4fc792b89b0af https://git.kernel.org/stable/c/6f8f1c27b577de15f69fefce3c502bb6300d825c https://git.kernel.org/stable/c/e1e10a390fd9479209c4d834d916ca5e6d5d396b https://git.kernel.org/stable/c/eecb4df8ec9f896b19ee05bfa632ac6c1dcd8f21

Frequently Asked Questions

What is CVE-2021-46994? +

In the Linux kernel, the following vulnerability has been resolved: can: mcp251x: fix resume from sleep before interface was brought up Since 8ce8c0abcba3 the driver queues work via priv->restart_work when resuming after suspend, even when the interface was not previously enabled. This causes a null dereference error as the workqueue is only allocated and initialized in mcp251x_open(). To fix this we move the workqueue init to mcp251x_can_probe() as there is no reason to do it later and repeat it whenever mcp251x_open() is called. [mkl: fix error handling in mcp251x_stop()] It has a CVSS v3.1 base score of 5.5 (MEDIUM).

How severe is CVE-2021-46994? +

CVE-2021-46994 has a CVSS v3.1 score of 5.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2021-46994? +

CVE-2021-46994 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2021-46994? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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