PT-2024-11448 · Linux+3 · Linux Kernel+3
Published
2021-10-15
·
Updated
2025-09-29
·
CVE-2021-47454
CVSS v3.1
5.5
Medium
| Vector | AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
Name of the Vulnerable Software and Affected Versions
Linux kernel versions prior to 5.15.0-rc2+
Description
The issue arises when a CPU is offlined and then onlined again with PREEMPT COUNT=y, resulting in a BUG: scheduling while atomic error. This occurs because the arch cpu idle dead() function decrements the idle task's preempt count. However, due to changes in commits 2c669ef6979c and f1a0a376ca0c, the justification for this behavior no longer holds, and the idle task should not re-enable preemption. The fix involves removing the vestigial preempt enable() from the CPU offline path.
Recommendations
At the moment, there is no information about a newer version that contains a fix for this vulnerability.
Race Condition
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Weakness Enumeration
Related Identifiers
Affected Products
Astra Linux
Linux Kernel
Red Hat
Suse