Cloudanix VulnDB

CVE-2024-50249

Medium · 5.5

CVSS

5.5

EPSS

0.2%

Published

Nov 9, 2024

CISA due date

—

Cloudanix analysis

Schedule a fix SSVC: Track

A locking mistake inside the Linux kernel can make systems using modern CPU power management crash or become unstable under normal workload changes.

Exploitation
Local Privilege
Attacker needs
Low Privilege
Complexity
Low
Impact
Denial Of Service
Component
OS kernel
Class
Race Condition
Remediation
Upgrade
Effort
Medium
Patch risk
Low

What it actually does

The ACPI CPPC driver uses a regular spinlock (rmw_lock) inside cpc_write() while callers such as sugov_update_shared() already hold a raw_spinlock; the resulting lock-order violation triggers an invalid-wait-context BUG in the scheduler.

Why it matters to the business

Linux systems performing CPU frequency scaling under load can experience kernel panics or worker-thread stalls, leading to degraded performance, unexpected reboots, and service disruption on servers and embedded devices.

How an attack unfolds

An attacker with local code execution triggers the cpufreq fast-switch path while the scheduler holds a raw_spinlock; the mismatched spinlock acquisition inside cpc_write() violates the kernel's wait-type rules and crashes the system. No remote vector or privilege escalation is present.

How to fix it

Upgrade the Linux kernel to commit 98f7e32f20d28ec452afb208f9cffc08448a2652 or later; rebuild and reboot with the patched kernel. No configuration workaround exists.

How to confirm the fix worked

Confirm the running kernel contains commit 98f7e32f20d28ec452afb208f9cffc08448a2652; verify that the rmw_lock declaration and acquisition sites now use raw_spin_lock_irqsave/raw_spin_unlock_irqrestore.

Typical attack path

  1. Obtain local execution on a Linux system using ACPI CPPC and cpufreq
  2. Induce frequent CPU load changes that invoke sugov_update_shared
  3. Force cppc_cpufreq_fast_switch to call cpc_write while holding raw_spin_rq_lock
  4. Trigger the spinlock acquisition inside the raw-spinlock context, producing the BUG

How to detect it

Search kernel logs for the string 'BUG: Invalid wait context' together with 'cpc_write' and 'rmw_lock'; inspect crash dumps for the call chain involving sugov_update_shared and cppc_set_perf.

  • BUG: Invalid wait context
  • cpc_write+0xcc/0x370
  • cppc_set_perf+0xa0/0x3a8
  • sugov_update_shared+0x234/0x280

What your security team should do

  • Prioritize patching kernel packages on all production Linux hosts within the next maintenance window
  • Reboot affected systems after package installation to load the fixed kernel
  • Monitor vendor advisories for backported fixes in distribution kernels

The record

In the Linux kernel, the following vulnerability has been resolved: ACPI: CPPC: Make rmw_lock a raw_spin_lock The following BUG was triggered: ============================= [ BUG: Invalid wait context ] 6.12.0-rc2-XXX #406 Not tainted ----------------------------- kworker/1:1/62 is trying to lock: ffffff8801593030 (&cpc_ptr->rmw_lock){+.+.}-{3:3}, at: cpc_write+0xcc/0x370 other info that might help us debug this: context-{5:5} 2 locks held by kworker/1:1/62: #0: ffffff897ef5ec98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2c/0x50 #1: ffffff880154e238 (&sg_policy->update_lock){....}-{2:2}, at: sugov_update_shared+0x3c/0x280 stack backtrace: CPU: 1 UID: 0 PID: 62 Comm: kworker/1:1 Not tainted 6.12.0-rc2-g9654bd3e8806 #406 Workqueue: 0x0 (events) Call trace: dump_backtrace+0xa4/0x130 show_stack+0x20/0x38 dump_stack_lvl+0x90/0xd0 dump_stack+0x18/0x28 __lock_acquire+0x480/0x1ad8 lock_acquire+0x114/0x310 _raw_spin_lock+0x50/0x70 cpc_write+0xcc/0x370 cppc_set_perf+0xa0/0x3a8 cppc_cpufreq_fast_switch+0x40/0xc0 cpufreq_driver_fast_switch+0x4c/0x218 sugov_update_shared+0x234/0x280 update_load_avg+0x6ec/0x7b8 dequeue_entities+0x108/0x830 dequeue_task_fair+0x58/0x408 __schedule+0x4f0/0x1070 schedule+0x54/0x130 worker_thread+0xc0/0x2e8 kthread+0x130/0x148 ret_from_fork+0x10/0x20 sugov_update_shared() locks a raw_spinlock while cpc_write() locks a spinlock. To have a correct wait-type order, update rmw_lock to a raw spinlock and ensure that interrupts will be disabled on the CPU holding it. [ rjw: Changelog edits ]

Affected packages

Ecosystem Package Introduced Fixed
Debian:11 linux-6.1 0 6.1.119-1~deb11u1
Debian:12 linux 0 No fix
Debian:12 linux 0 6.1.119-1
Debian:13 linux 0 No fix
Debian:13 linux 0 6.11.7-1
Linux Kernel 5.15.168 5.15.171
Mageia:9 bluez 0 5.79-1.mga9
Mageia:9 kernel 0 6.6.61-1.mga9
Mageia:9 kernel-linus 0 6.6.61-1.mga9
Mageia:9 kmod-virtualbox 0 7.0.20-58.mga9
Mageia:9 kmod-xtables-addons 0 3.24-66.mga9
SUSE:Linux Enterprise High Availability Extension 15 SP5 kernel-default 0 5.14.21-150500.55.88.1
SUSE:Linux Enterprise High Availability Extension 15 SP6 kernel-default 0 6.4.0-150600.23.30.1
SUSE:Linux Enterprise Live Patching 15 SP5 kernel-default 0 5.14.21-150500.55.88.1
SUSE:Linux Enterprise Live Patching 15 SP5 kernel-livepatch-SLE15-SP5-RT_Update_23 0 1-150500.11.3.1
SUSE:Linux Enterprise Live Patching 15 SP5 kernel-livepatch-SLE15-SP5_Update_21 0 1-150500.11.5.1
SUSE:Linux Enterprise Live Patching 15 SP6 kernel-default 0 6.4.0-150600.23.30.1
SUSE:Linux Enterprise Live Patching 15 SP6 kernel-livepatch-SLE15-SP6-RT_Update_6 0 1-150600.1.3.1
SUSE:Linux Enterprise Live Patching 15 SP6 kernel-livepatch-SLE15-SP6_Update_6 0 1-150600.13.3.5
SUSE:Linux Enterprise Micro 5.5 kernel-default 0 5.14.21-150500.55.88.1
SUSE:Linux Enterprise Micro 5.5 kernel-default-base 0 5.14.21-150500.55.88.1.150500.6.39.4
SUSE:Linux Enterprise Micro 5.5 kernel-rt 0 5.14.21-150500.13.79.1
SUSE:Linux Enterprise Micro 5.5 kernel-source-rt 0 5.14.21-150500.13.79.1
SUSE:Linux Enterprise Module for Basesystem 15 SP5 kernel-64kb 0 5.14.21-150500.55.88.1
SUSE:Linux Enterprise Module for Basesystem 15 SP5 kernel-default 0 5.14.21-150500.55.88.1
SUSE:Linux Enterprise Module for Basesystem 15 SP5 kernel-default-base 0 5.14.21-150500.55.88.1.150500.6.39.4
SUSE:Linux Enterprise Module for Basesystem 15 SP5 kernel-source 0 5.14.21-150500.55.88.1
SUSE:Linux Enterprise Module for Basesystem 15 SP5 kernel-zfcpdump 0 5.14.21-150500.55.88.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-64kb 0 6.4.0-150600.23.30.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-default 0 6.4.0-150600.23.30.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-default-base 0 6.4.0-150600.23.30.1.150600.12.12.6
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-source 0 6.4.0-150600.23.30.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-zfcpdump 0 6.4.0-150600.23.30.1
SUSE:Linux Enterprise Module for Confidential Computing Technical Preview 15 SP6 kernel-coco 0 6.4.0-15061.9.coco15sp6.1
SUSE:Linux Enterprise Module for Confidential Computing Technical Preview 15 SP6 kernel-coco_debug 0 6.4.0-15061.9.coco15sp6.1
SUSE:Linux Enterprise Module for Confidential Computing Technical Preview 15 SP6 kernel-source-coco 0 6.4.0-15061.9.coco15sp6.1
SUSE:Linux Enterprise Module for Confidential Computing Technical Preview 15 SP6 kernel-syms-coco 0 6.4.0-15061.9.coco15sp6.1
SUSE:Linux Enterprise Module for Development Tools 15 SP5 kernel-docs 0 5.14.21-150500.55.88.1
SUSE:Linux Enterprise Module for Development Tools 15 SP5 kernel-obs-build 0 5.14.21-150500.55.88.1
SUSE:Linux Enterprise Module for Development Tools 15 SP5 kernel-source 0 5.14.21-150500.55.88.1
SUSE:Linux Enterprise Module for Development Tools 15 SP5 kernel-syms 0 5.14.21-150500.55.88.1
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-docs 0 6.4.0-150600.23.30.1
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-obs-build 0 6.4.0-150600.23.30.1
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-source 0 6.4.0-150600.23.30.1
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-syms 0 6.4.0-150600.23.30.1
SUSE:Linux Enterprise Module for Legacy 15 SP5 kernel-default 0 5.14.21-150500.55.88.1
SUSE:Linux Enterprise Module for Legacy 15 SP6 kernel-default 0 6.4.0-150600.23.30.1
SUSE:Linux Enterprise Module for Public Cloud 15 SP5 kernel-azure 0 5.14.21-150500.33.75.1
SUSE:Linux Enterprise Module for Public Cloud 15 SP5 kernel-source-azure 0 5.14.21-150500.33.75.1
SUSE:Linux Enterprise Module for Public Cloud 15 SP5 kernel-syms-azure 0 5.14.21-150500.33.75.1
SUSE:Linux Enterprise Module for Public Cloud 15 SP6 kernel-azure 0 6.4.0-150600.8.20.1
SUSE:Linux Enterprise Module for Public Cloud 15 SP6 kernel-source-azure 0 6.4.0-150600.8.20.1
SUSE:Linux Enterprise Module for Public Cloud 15 SP6 kernel-syms-azure 0 6.4.0-150600.8.20.1
SUSE:Linux Enterprise Workstation Extension 15 SP6 kernel-default 0 6.4.0-150600.23.30.1
SUSE:Real Time Module 15 SP5 kernel-rt 0 5.14.21-150500.13.79.1
SUSE:Real Time Module 15 SP5 kernel-rt_debug 0 5.14.21-150500.13.79.1
SUSE:Real Time Module 15 SP5 kernel-source-rt 0 5.14.21-150500.13.79.1
SUSE:Real Time Module 15 SP5 kernel-syms-rt 0 5.14.21-150500.13.79.1
SUSE:Real Time Module 15 SP6 kernel-rt 0 6.4.0-150600.10.20.1
SUSE:Real Time Module 15 SP6 kernel-rt_debug 0 6.4.0-150600.10.20.1
SUSE:Real Time Module 15 SP6 kernel-source-rt 0 6.4.0-150600.10.20.1
SUSE:Real Time Module 15 SP6 kernel-syms-rt 0 6.4.0-150600.10.20.1
Ubuntu:16.04:LTS linux-hwe-edge 0 No fix
Ubuntu:18.04:LTS linux-aws-5.0 0 No fix
Ubuntu:18.04:LTS linux-aws-5.3 0 No fix
Ubuntu:18.04:LTS linux-azure 0 No fix
Ubuntu:18.04:LTS linux-azure-5.3 0 No fix
Ubuntu:18.04:LTS linux-azure-edge 0 No fix
Ubuntu:18.04:LTS linux-gcp 0 No fix
Ubuntu:18.04:LTS linux-gcp-5.3 0 No fix
Ubuntu:18.04:LTS linux-gke-4.15 0 No fix
Ubuntu:18.04:LTS linux-gke-5.4 0 No fix
Ubuntu:18.04:LTS linux-gkeop-5.4 0 No fix
Ubuntu:18.04:LTS linux-hwe 0 No fix
Ubuntu:18.04:LTS linux-hwe-edge 0 No fix
Ubuntu:18.04:LTS linux-oem 0 No fix
Ubuntu:18.04:LTS linux-oracle-5.0 0 No fix
Ubuntu:18.04:LTS linux-oracle-5.3 0 No fix
Ubuntu:20.04:LTS linux 0 No fix
Ubuntu:20.04:LTS linux-aws 0 No fix
Ubuntu:20.04:LTS linux-aws-5.11 0 No fix
Ubuntu:20.04:LTS linux-aws-5.13 0 No fix
Ubuntu:20.04:LTS linux-aws-5.15 0 No fix
Ubuntu:20.04:LTS linux-aws-5.15 0 5.15.0-1080.87~20.04.1
Ubuntu:20.04:LTS linux-aws-5.8 0 No fix
Ubuntu:20.04:LTS linux-azure 0 No fix
Ubuntu:20.04:LTS linux-azure-5.11 0 No fix
Ubuntu:20.04:LTS linux-azure-5.13 0 No fix
Ubuntu:20.04:LTS linux-azure-5.15 0 No fix
Ubuntu:20.04:LTS linux-azure-5.15 0 5.15.0-1081.90~20.04.1
Ubuntu:20.04:LTS linux-azure-5.8 0 No fix
Ubuntu:20.04:LTS linux-azure-fde 0 No fix
Ubuntu:20.04:LTS linux-azure-fde-5.15 0 No fix
Ubuntu:20.04:LTS linux-bluefield 0 No fix
Ubuntu:20.04:LTS linux-gcp 0 No fix
Ubuntu:20.04:LTS linux-gcp-5.11 0 No fix
Ubuntu:20.04:LTS linux-gcp-5.13 0 No fix
Ubuntu:20.04:LTS linux-gcp-5.15 0 No fix
Ubuntu:20.04:LTS linux-gcp-5.15 0 5.15.0-1077.86~20.04.1
Ubuntu:20.04:LTS linux-gcp-5.8 0 No fix
Ubuntu:20.04:LTS linux-gke 0 No fix
Ubuntu:20.04:LTS linux-gke-5.15 0 No fix
Ubuntu:20.04:LTS linux-gkeop 0 No fix
Ubuntu:20.04:LTS linux-gkeop-5.15 0 No fix
Ubuntu:20.04:LTS linux-hwe-5.11 0 No fix
Ubuntu:20.04:LTS linux-hwe-5.13 0 No fix
Ubuntu:20.04:LTS linux-hwe-5.15 0 No fix
Ubuntu:20.04:LTS linux-hwe-5.15 0 5.15.0-134.145~20.04.1
Ubuntu:20.04:LTS linux-hwe-5.8 0 No fix
Ubuntu:20.04:LTS linux-ibm 0 No fix
Ubuntu:20.04:LTS linux-ibm-5.15 0 No fix
Ubuntu:20.04:LTS linux-ibm-5.15 0 5.15.0-1074.77~20.04.1
Ubuntu:20.04:LTS linux-intel-5.13 0 No fix
Ubuntu:20.04:LTS linux-intel-iotg-5.15 0 No fix
Ubuntu:20.04:LTS linux-intel-iotg-5.15 0 5.15.0-1073.79~20.04.2
Ubuntu:20.04:LTS linux-iot 0 No fix
Ubuntu:20.04:LTS linux-kvm 0 No fix
Ubuntu:20.04:LTS linux-lowlatency-hwe-5.15 0 No fix
Ubuntu:20.04:LTS linux-lowlatency-hwe-5.15 0 5.15.0-133.143~20.04.1
Ubuntu:20.04:LTS linux-oem-5.10 0 No fix
Ubuntu:20.04:LTS linux-oem-5.13 0 No fix
Ubuntu:20.04:LTS linux-oem-5.14 0 No fix
Ubuntu:20.04:LTS linux-oem-5.6 0 No fix
Ubuntu:20.04:LTS linux-oracle 0 No fix
Ubuntu:20.04:LTS linux-oracle-5.11 0 No fix
Ubuntu:20.04:LTS linux-oracle-5.13 0 No fix
Ubuntu:20.04:LTS linux-oracle-5.15 0 No fix
Ubuntu:20.04:LTS linux-oracle-5.15 0 5.15.0-1075.81~20.04.1
Ubuntu:20.04:LTS linux-oracle-5.8 0 No fix
Ubuntu:20.04:LTS linux-raspi 0 No fix
Ubuntu:20.04:LTS linux-raspi2 0 No fix
Ubuntu:20.04:LTS linux-riscv 0 No fix
Ubuntu:20.04:LTS linux-riscv-5.11 0 No fix
Ubuntu:20.04:LTS linux-riscv-5.15 0 No fix
Ubuntu:20.04:LTS linux-riscv-5.15 0 5.15.0-1073.77~20.04.1
Ubuntu:20.04:LTS linux-riscv-5.8 0 No fix
Ubuntu:20.04:LTS linux-xilinx-zynqmp 0 No fix
Ubuntu:22.04:LTS linux 0 No fix
Ubuntu:22.04:LTS linux 0 5.15.0-133.144
Ubuntu:22.04:LTS linux-allwinner-5.19 0 No fix
Ubuntu:22.04:LTS linux-aws 0 No fix
Ubuntu:22.04:LTS linux-aws 0 5.15.0-1078.85
Ubuntu:22.04:LTS linux-aws-5.19 0 No fix
Ubuntu:22.04:LTS linux-aws-6.2 0 No fix
Ubuntu:22.04:LTS linux-aws-6.5 0 No fix
Ubuntu:22.04:LTS linux-aws-6.8 0 No fix
Ubuntu:22.04:LTS linux-aws-6.8 0 6.8.0-1027.29~22.04.1
Ubuntu:22.04:LTS linux-azure 0 No fix
Ubuntu:22.04:LTS linux-azure 0 5.15.0-1081.90
Ubuntu:22.04:LTS linux-azure-5.19 0 No fix
Ubuntu:22.04:LTS linux-azure-6.2 0 No fix
Ubuntu:22.04:LTS linux-azure-6.5 0 No fix
Ubuntu:22.04:LTS linux-azure-6.8 0 No fix
Ubuntu:22.04:LTS linux-azure-6.8 0 6.8.0-1027.32~22.04.1
Ubuntu:22.04:LTS linux-azure-fde 0 No fix
Ubuntu:22.04:LTS linux-azure-fde 0 5.15.0-1081.90.1
Ubuntu:22.04:LTS linux-azure-fde-5.19 0 No fix
Ubuntu:22.04:LTS linux-azure-fde-6.2 0 No fix
Ubuntu:22.04:LTS linux-gcp 0 No fix
Ubuntu:22.04:LTS linux-gcp 0 5.15.0-1077.86
Ubuntu:22.04:LTS linux-gcp-5.19 0 No fix
Ubuntu:22.04:LTS linux-gcp-6.2 0 No fix
Ubuntu:22.04:LTS linux-gcp-6.5 0 No fix
Ubuntu:22.04:LTS linux-gcp-6.8 0 No fix
Ubuntu:22.04:LTS linux-gcp-6.8 0 6.8.0-1028.30~22.04.1
Ubuntu:22.04:LTS linux-gke 0 No fix
Ubuntu:22.04:LTS linux-gke 0 5.15.0-1075.81
Ubuntu:22.04:LTS linux-gkeop 0 No fix
Ubuntu:22.04:LTS linux-gkeop 0 5.15.0-1060.68
Ubuntu:22.04:LTS linux-hwe-5.19 0 No fix
Ubuntu:22.04:LTS linux-hwe-6.2 0 No fix
Ubuntu:22.04:LTS linux-hwe-6.5 0 No fix
Ubuntu:22.04:LTS linux-hwe-6.8 0 No fix
Ubuntu:22.04:LTS linux-hwe-6.8 0 6.8.0-58.60~22.04.1
Ubuntu:22.04:LTS linux-ibm 0 No fix
Ubuntu:22.04:LTS linux-ibm 0 5.15.0-1070.73
Ubuntu:22.04:LTS linux-ibm-6.8 0 6.8.0-1024.24~22.04.1
Ubuntu:22.04:LTS linux-intel-iot-realtime 0 No fix
Ubuntu:22.04:LTS linux-intel-iotg 0 No fix
Ubuntu:22.04:LTS linux-intel-iotg 0 5.15.0-1073.79
Ubuntu:22.04:LTS linux-kvm 0 No fix
Ubuntu:22.04:LTS linux-kvm 0 5.15.0-1076.81
Ubuntu:22.04:LTS linux-lowlatency 0 No fix
Ubuntu:22.04:LTS linux-lowlatency 0 5.15.0-133.143
Ubuntu:22.04:LTS linux-lowlatency-hwe-5.19 0 No fix
Ubuntu:22.04:LTS linux-lowlatency-hwe-6.2 0 No fix
Ubuntu:22.04:LTS linux-lowlatency-hwe-6.5 0 No fix
Ubuntu:22.04:LTS linux-lowlatency-hwe-6.8 0 No fix
Ubuntu:22.04:LTS linux-lowlatency-hwe-6.8 0 6.8.0-58.60.1~22.04.1
Ubuntu:22.04:LTS linux-nvidia 0 No fix
Ubuntu:22.04:LTS linux-nvidia 0 5.15.0-1072.73
Ubuntu:22.04:LTS linux-nvidia-6.2 0 No fix
Ubuntu:22.04:LTS linux-nvidia-6.5 0 No fix
Ubuntu:22.04:LTS linux-nvidia-6.8 0 No fix
Ubuntu:22.04:LTS linux-nvidia-6.8 0 6.8.0-1026.29~22.04.1
Ubuntu:22.04:LTS linux-nvidia-tegra 0 5.15.0-1033.33
Ubuntu:22.04:LTS linux-nvidia-tegra-igx 0 5.15.0-1021.21
Ubuntu:22.04:LTS linux-oem-5.17 0 No fix
Ubuntu:22.04:LTS linux-oem-6.0 0 No fix
Ubuntu:22.04:LTS linux-oem-6.1 0 No fix

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