Cloudanix VulnDB

CVE-2024-56585

None

CVSS

—

EPSS

0.2%

Published

Dec 27, 2024

CISA due date

—

Cloudanix analysis

Schedule a fix SSVC: Track

A startup problem in the Linux kernel on certain processors using real-time settings could cause the machine to crash before it finishes booting.

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

What it actually does

The flaw triggers rt_spin_lock() (which sleeps under PREEMPT_RT) from atomic context during early TLB and per-CPU trap initialization on LoongArch because NUMA page allocation remains enabled under zone and pcp locks.

Why it matters to the business

Systems using LoongArch hardware with PREEMPT_RT kernels may panic or fail to boot, causing deployment delays for real-time workloads; low overall urgency given absent KEV listing and minimal EPSS.

How an attack unfolds

An attacker with the ability to boot a vulnerable kernel on LoongArch PREEMPT_RT hardware can induce the sleeping-in-atomic BUG during secondary CPU bring-up in swapper/1; no remote or post-boot exploitation path exists.

How to fix it

Apply the upstream fix in commit 08715b741f9b2a925d6485491e4907f3b29bac70 or later; for PREEMPT_RT kernels completely disable NUMA optimization in setup_tlb_handler and related paths.

How to confirm the fix worked

Confirm kernel version contains 08715b741f9b2a925d6485491e4907f3b29bac70, verify PREEMPT_RT config builds without the sleeping-in-atomic BUG on LoongArch hardware, and check boot logs for absence of the spinlock_rt.c warning.

Typical attack path

  1. Boot Linux kernel with PREEMPT_RT and LoongArch NUMA support enabled
  2. Reach per_cpu_trap_init during smpboot_entry on secondary CPU
  3. Enter tlb_init which performs GFP_ATOMIC allocation under rt_spinlocks
  4. Trigger __might_resched BUG when rt_spin_lock attempts to sleep

How to detect it

Inspect early boot logs (dmesg, serial console) for the exact BUG string referencing spinlock_rt.c together with stack frames showing tlb_init, per_cpu_trap_init, or get_page_from_freelist during swapper/1 initialization.

  • BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
  • tlb_init+0x1ac/0x298
  • per_cpu_trap_init+0x114/0x140
  • swapper/1

What your security team should do

  • Prioritize upgrade to fixed kernel on all LoongArch PREEMPT_RT deployments
  • Test full boot sequence on representative hardware before production rollout
  • Add boot-time log monitoring for atomic-context violations on affected architectures

The record

In the Linux kernel, the following vulnerability has been resolved: LoongArch: Fix sleeping in atomic context for PREEMPT_RT Commit bab1c299f3945ffe79 ("LoongArch: Fix sleeping in atomic context in setup_tlb_handler()") changes the gfp flag from GFP_KERNEL to GFP_ATOMIC for alloc_pages_node(). However, for PREEMPT_RT kernels we can still get a "sleeping in atomic context" error: [ 0.372259] BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 [ 0.372266] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 0, name: swapper/1 [ 0.372268] preempt_count: 1, expected: 0 [ 0.372270] RCU nest depth: 1, expected: 1 [ 0.372272] 3 locks held by swapper/1/0: [ 0.372274] #0: 900000000c9f5e60 (&pcp->lock){+.+.}-{3:3}, at: get_page_from_freelist+0x524/0x1c60 [ 0.372294] #1: 90000000087013b8 (rcu_read_lock){....}-{1:3}, at: rt_spin_trylock+0x50/0x140 [ 0.372305] #2: 900000047fffd388 (&zone->lock){+.+.}-{3:3}, at: __rmqueue_pcplist+0x30c/0xea0 [ 0.372314] irq event stamp: 0 [ 0.372316] hardirqs last enabled at (0): [<0000000000000000>] 0x0 [ 0.372322] hardirqs last disabled at (0): [<9000000005947320>] copy_process+0x9c0/0x26e0 [ 0.372329] softirqs last enabled at (0): [<9000000005947320>] copy_process+0x9c0/0x26e0 [ 0.372335] softirqs last disabled at (0): [<0000000000000000>] 0x0 [ 0.372341] CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.12.0-rc7+ #1891 [ 0.372346] Hardware name: Loongson Loongson-3A5000-7A1000-1w-CRB/Loongson-LS3A5000-7A1000-1w-CRB, BIOS vUDK2018-LoongArch-V2.0.0-prebeta9 10/21/2022 [ 0.372349] Stack : 0000000000000089 9000000005a0db9c 90000000071519c8 9000000100388000 [ 0.372486] 900000010038b890 0000000000000000 900000010038b898 9000000007e53788 [ 0.372492] 900000000815bcc8 900000000815bcc0 900000010038b700 0000000000000001 [ 0.372498] 0000000000000001 4b031894b9d6b725 00000000055ec000 9000000100338fc0 [ 0.372503] 00000000000000c4 0000000000000001 000000000000002d 0000000000000003 [ 0.372509] 0000000000000030 0000000000000003 00000000055ec000 0000000000000003 [ 0.372515] 900000000806d000 9000000007e53788 00000000000000b0 0000000000000004 [ 0.372521] 0000000000000000 0000000000000000 900000000c9f5f10 0000000000000000 [ 0.372526] 90000000076f12d8 9000000007e53788 9000000005924778 0000000000000000 [ 0.372532] 00000000000000b0 0000000000000004 0000000000000000 0000000000070000 [ 0.372537] ... [ 0.372540] Call Trace: [ 0.372542] [<9000000005924778>] show_stack+0x38/0x180 [ 0.372548] [<90000000071519c4>] dump_stack_lvl+0x94/0xe4 [ 0.372555] [<900000000599b880>] __might_resched+0x1a0/0x260 [ 0.372561] [<90000000071675cc>] rt_spin_lock+0x4c/0x140 [ 0.372565] [<9000000005cbb768>] __rmqueue_pcplist+0x308/0xea0 [ 0.372570] [<9000000005cbed84>] get_page_from_freelist+0x564/0x1c60 [ 0.372575] [<9000000005cc0d98>] __alloc_pages_noprof+0x218/0x1820 [ 0.372580] [<900000000593b36c>] tlb_init+0x1ac/0x298 [ 0.372585] [<9000000005924b74>] per_cpu_trap_init+0x114/0x140 [ 0.372589] [<9000000005921964>] cpu_probe+0x4e4/0xa60 [ 0.372592] [<9000000005934874>] start_secondary+0x34/0xc0 [ 0.372599] [<900000000715615c>] smpboot_entry+0x64/0x6c This is because in PREEMPT_RT kernels normal spinlocks are replaced by rt spinlocks and rt_spin_lock() will cause sleeping. Fix it by disabling NUMA optimization completely for PREEMPT_RT kernels.

Affected packages

Ecosystem Package Introduced Fixed
Debian:11 linux-6.1 0 6.1.128-1~deb11u1
Debian:11 linux-6.1 0 6.1.6.1.128-1~deb11u1
Debian:12 linux 0 6.1.123-1
Debian:13 linux 0 6.12.5-1
Linux Kernel 5.19.0 6.1.120
Mageia:9 dwarves 0 1.29-1.mga9
Mageia:9 kernel 0 6.6.74-1.mga9
Mageia:9 kernel-linus 0 6.6.74-1.mga9
Mageia:9 kmod-virtualbox 0 7.0.24-64.mga9
Mageia:9 kmod-xtables-addons 0 3.24-70.mga9
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-5.8 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-5.8 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-5.8 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-5.8 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-intel-5.13 0 No fix
Ubuntu:20.04:LTS linux-intel-iotg-5.15 0 No fix
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-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-5.8 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-5.8 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-allwinner-5.19 0 No fix
Ubuntu:22.04:LTS linux-aws 0 No fix
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-azure 0 No fix
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-fde 0 No fix
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-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-gke 0 No fix
Ubuntu:22.04:LTS linux-gkeop 0 No fix
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-ibm 0 No fix
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-kvm 0 No fix
Ubuntu:22.04:LTS linux-lowlatency 0 No fix
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-nvidia 0 No fix
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-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
Ubuntu:22.04:LTS linux-oem-6.5 0 No fix
Ubuntu:22.04:LTS linux-oracle 0 No fix
Ubuntu:22.04:LTS linux-oracle-6.5 0 No fix
Ubuntu:22.04:LTS linux-oracle-6.8 0 No fix
Ubuntu:22.04:LTS linux-raspi 0 No fix
Ubuntu:22.04:LTS linux-realtime 0 No fix
Ubuntu:22.04:LTS linux-riscv 0 No fix
Ubuntu:22.04:LTS linux-riscv-5.19 0 No fix
Ubuntu:22.04:LTS linux-riscv-6.5 0 No fix
Ubuntu:22.04:LTS linux-riscv-6.8 0 No fix
Ubuntu:22.04:LTS linux-starfive-5.19 0 No fix
Ubuntu:22.04:LTS linux-starfive-6.2 0 No fix
Ubuntu:22.04:LTS linux-starfive-6.5 0 No fix
Ubuntu:22.04:LTS linux-xilinx-zynqmp 0 No fix
Ubuntu:22.04:LTS:for:NVIDIA:BlueField linux-bluefield 0 No fix
Ubuntu:24.04:LTS linux 0 No fix
Ubuntu:24.04:LTS linux-aws 0 No fix
Ubuntu:24.04:LTS linux-azure 0 No fix
Ubuntu:24.04:LTS linux-azure-fde 0 No fix
Ubuntu:24.04:LTS linux-gcp 0 No fix
Ubuntu:24.04:LTS linux-gke 0 No fix
Ubuntu:24.04:LTS linux-gkeop 0 No fix
Ubuntu:24.04:LTS linux-hwe-6.11 0 No fix
Ubuntu:24.04:LTS linux-ibm 0 No fix
Ubuntu:24.04:LTS linux-intel 0 No fix
Ubuntu:24.04:LTS linux-lowlatency 0 No fix
Ubuntu:24.04:LTS linux-lowlatency-hwe-6.11 0 No fix
Ubuntu:24.04:LTS linux-nvidia 0 No fix
Ubuntu:24.04:LTS linux-nvidia-lowlatency 0 No fix
Ubuntu:24.04:LTS linux-oem-6.11 0 No fix
Ubuntu:24.04:LTS linux-oem-6.8 0 No fix
Ubuntu:24.04:LTS linux-oracle 0 No fix
Ubuntu:24.04:LTS linux-raspi 0 No fix
Ubuntu:24.04:LTS linux-raspi-realtime 0 No fix
Ubuntu:24.04:LTS linux-realtime 0 No fix
Ubuntu:24.04:LTS linux-riscv 0 No fix
Ubuntu:24.10 linux 0 No fix
Ubuntu:24.10 linux-aws 0 No fix
Ubuntu:24.10 linux-azure 0 No fix
Ubuntu:24.10 linux-gcp 0 No fix
Ubuntu:24.10 linux-lowlatency 0 No fix
Ubuntu:24.10 linux-oracle 0 No fix
Ubuntu:24.10 linux-raspi 0 No fix
Ubuntu:24.10 linux-realtime 0 No fix
Ubuntu:24.10 linux-riscv 0 No fix
Ubuntu:Pro:14.04:LTS linux 0 No fix
Ubuntu:Pro:14.04:LTS linux-aws 0 No fix
Ubuntu:Pro:14.04:LTS linux-azure 0 No fix
Ubuntu:Pro:14.04:LTS linux-lts-xenial 0 No fix
Ubuntu:Pro:16.04:LTS linux 0 No fix
Ubuntu:Pro:16.04:LTS linux-aws 0 No fix
Ubuntu:Pro:16.04:LTS linux-aws-hwe 0 No fix
Ubuntu:Pro:16.04:LTS linux-azure 0 No fix
Ubuntu:Pro:16.04:LTS linux-gcp 0 No fix
Ubuntu:Pro:16.04:LTS linux-hwe 0 No fix
Ubuntu:Pro:16.04:LTS linux-hwe-edge 0 No fix
Ubuntu:Pro:16.04:LTS linux-kvm 0 No fix
Ubuntu:Pro:16.04:LTS linux-oracle 0 No fix
Ubuntu:Pro:18.04:LTS linux 0 No fix
Ubuntu:Pro:18.04:LTS linux-aws 0 No fix
Ubuntu:Pro:18.04:LTS linux-aws-5.0 0 No fix
Ubuntu:Pro:18.04:LTS linux-aws-5.3 0 No fix
Ubuntu:Pro:18.04:LTS linux-aws-5.4 0 No fix
Ubuntu:Pro:18.04:LTS linux-azure 0 No fix
Ubuntu:Pro:18.04:LTS linux-azure-4.15 0 No fix
Ubuntu:Pro:18.04:LTS linux-azure-5.3 0 No fix
Ubuntu:Pro:18.04:LTS linux-azure-5.4 0 No fix
Ubuntu:Pro:18.04:LTS linux-azure-edge 0 No fix
Ubuntu:Pro:18.04:LTS linux-gcp 0 No fix
Ubuntu:Pro:18.04:LTS linux-gcp-4.15 0 No fix
Ubuntu:Pro:18.04:LTS linux-gcp-5.3 0 No fix
Ubuntu:Pro:18.04:LTS linux-gcp-5.4 0 No fix
Ubuntu:Pro:18.04:LTS linux-gke-4.15 0 No fix
Ubuntu:Pro:18.04:LTS linux-gke-5.4 0 No fix
Ubuntu:Pro:18.04:LTS linux-gkeop-5.4 0 No fix
Ubuntu:Pro:18.04:LTS linux-hwe 0 No fix
Ubuntu:Pro:18.04:LTS linux-hwe-5.4 0 No fix
Ubuntu:Pro:18.04:LTS linux-hwe-edge 0 No fix
Ubuntu:Pro:18.04:LTS linux-ibm-5.4 0 No fix
Ubuntu:Pro:18.04:LTS linux-kvm 0 No fix
Ubuntu:Pro:18.04:LTS linux-oem 0 No fix
Ubuntu:Pro:18.04:LTS linux-oracle 0 No fix

Related vulnerabilities