CVE-2021-47424

What it is

In the Linux kernel, the following vulnerability has been resolved: i40e: Fix freeing of uninitialized misc IRQ vector When VSI set up failed in i40e_probe() as part of PF switch set up driver was trying to free misc IRQ vectors in i40e_clear_interrupt_scheme and produced a kernel Oops: Trying to free already-free IRQ 266 WARNING: CPU: 0 PID: 5 at kernel/irq/manage.c:1731 __free_irq+0x9a/0x300 Workqueue: events work_for_cpu_fn RIP: 0010:__free_irq+0x9a/0x300 Call Trace: ? synchronize_irq+0x3a/0xa0 free_irq+0x2e/0x60 i40e_clear_interrupt_scheme+0x53/0x190 [i40e] i40e_probe.part.108+0x134b/0x1a40 [i40e] ? kmem_cache_alloc+0x158/0x1c0 ? acpi_ut_update_ref_count.part.1+0x8e/0x345 ? acpi_ut_update_object_reference+0x15e/0x1e2 ? strstr+0x21/0x70 ? irq_get_irq_data+0xa/0x20 ? mp_check_pin_attr+0x13/0xc0 ? irq_get_irq_data+0xa/0x20 ? mp_map_pin_to_irq+0xd3/0x2f0 ? acpi_register_gsi_ioapic+0x93/0x170 ? pci_conf1_read+0xa4/0x100 ? pci_bus_read_config_word+0x49/0x70 ? do_pci_enable_device+0xcc/0x100 local_pci_probe+0x41/0x90 work_for_cpu_fn+0x16/0x20 process_one_work+0x1a7/0x360 worker_thread+0x1cf/0x390 ? create_worker+0x1a0/0x1a0 kthread+0x112/0x130 ? kthread_flush_work_fn+0x10/0x10 ret_from_fork+0x1f/0x40 The problem is that at that point misc IRQ vectors were not allocated yet and we get a call trace that driver is trying to free already free IRQ vectors. Add a check in i40e_clear_interrupt_scheme for __I40E_MISC_IRQ_REQUESTED PF state before calling i40e_free_misc_vector. This state is set only if misc IRQ vectors were properly initialized.

At a glance

Exploitability

Can be exploited locally on the machine with a low-privilege account. High risk of service disruption.

Exploit odds

0.2% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2024-05-21 15:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 04:17 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.2% in the next 30 days (EPSS).
• Severity: 5.5 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2024-05-21 15:15 UTC

Last modified

2026-06-17 04:17 UTC

Exploit probability

0.2% · EPSS, next 30 days

Weakness

CWE-908

Record status

Analyzed

Affected

• Linux Kernel < 4.19.211
• Linux Kernel < 5.4.153
• Linux Kernel < 5.10.73
• Linux Kernel < 5.14.12
• Linux Kernel 5.15

Attack profile CVSS 3.1 · 5.5

Attack vector

Local

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2021-47424.md and follow it. Check whether this project is affected by CVE-2021-47424. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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