CVE-2024-35929
kernel: rcu/nocb: Fix WARN_ON_ONCE() in the rcu_nocb_bypass_lock()
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · May 19, 2024
Updated · November 21, 2025
Description
This is a vulnerability in the Linux kernel's RCU (Read-Copy Update) subsystem, specifically affecting configurations that enable lazy RCU operations (CONFIG_RCU_NOCB_CPU_DEFAULT_ALL and CONFIG_RCU_LAZY). Under certain conditions, operations like writing to /proc/sys/vm/drop_caches could trigger warnings due to unsafe handling of the RCU nocb bypass queue. This issue may result in system instability or undefined behavior. The vulnerability has been resolved by improving how the nocb bypass queue is managed to ensure safer concurrency. Users should update to a patched kernel version to prevent potential disruptions.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.1 · 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE not specified