Improper Locking Affecting kernel-rt-debug package, versions *


Severity

Recommended
0.0
medium
0
10

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
0.04% (6th percentile)

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  • Snyk IDSNYK-RHEL9-KERNELRTDEBUG-8263645
  • published23 Oct 2024
  • disclosed21 Oct 2024

Introduced: 21 Oct 2024

CVE-2024-49976  (opens in a new tab)
CWE-667  (opens in a new tab)

How to fix?

There is no fixed version for RHEL:9 kernel-rt-debug.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-rt-debug package and not the kernel-rt-debug package as distributed by RHEL. See How to fix? for RHEL:9 relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

tracing/timerlat: Drop interface_lock in stop_kthread()

stop_kthread() is the offline callback for "trace/osnoise:online", since commit 5bfbcd1ee57b ("tracing/timerlat: Add interface_lock around clearing of kthread in stop_kthread()"), the following ABBA deadlock scenario is introduced:

T1 | T2 [BP] | T3 [AP] osnoise_hotplug_workfn() | work_for_cpu_fn() | cpuhp_thread_fun() | _cpu_down() | osnoise_cpu_die() mutex_lock(&interface_lock) | | stop_kthread() | cpus_write_lock() | mutex_lock(&interface_lock) cpus_read_lock() | cpuhp_kick_ap() |

As the interface_lock here in just for protecting the "kthread" field of the osn_var, use xchg() instead to fix this issue. Also use for_each_online_cpu() back in stop_per_cpu_kthreads() as it can take cpu_read_lock() again.

CVSS Scores

version 3.1