CVE-2021-46994: can: mcp251x: fix resume from sleep before interface was brought up

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-02-28 · updated 2026-06-17
Weakness: CWE-476

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()]

Affected products

Linux kernel: from 5.5 before 5.10.38; from 5.11 before 5.11.22; from 5.12 before 5.12.5 — fixed in 5.10.38, 5.11.22, 5.12.5

How to fix

Upgrade to a fixed version: Linux kernel 5.10.38, 5.11.22, 5.12.5. Check the vendor advisory for mitigations.

References

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