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Fencer Vulns
medium 5.5

CVE-2021-47424 json

i40e: Fix freeing of uninitialized misc IRQ vector

published 2024-05-21 2 y ago modified 2026-06-17 4 mo ago also EUVD-2021-34429

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 12%
public exploits
0
none known

Summary

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.

Patch / fix

  • Linux Linux 4.19.211, 5.4.153, 5.10.73, 5.14.12, 5.15
  • linux Debian 14, Debian 13, Debian 12 5.14.12-1

debian advisories DEBIAN-CVE-2021-47424

  • linux Ubuntu 18.04 LTS 4.15.0-166.174
  • linux Ubuntu 20.04 LTS 5.4.0-92.103
  • linux-aws Ubuntu 18.04 LTS 4.15.0-1118.125
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1061.64
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1059.63
  • linux-ibm Ubuntu 20.04 LTS 5.4.0-1010.11
  • linux-kvm Ubuntu 18.04 LTS 4.15.0-1105.107
  • linux-kvm Ubuntu 20.04 LTS 5.4.0-1051.53

ubuntu advisories UBUNTU-CVE-2021-47424

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • dtb-aarch64 openSUSE Leap 15.5 5.14.21-150500.55.68.1
  • kernel-64kb SLE Module for Basesystem 15 SP5, openSUSE Leap 15.5 5.14.21-150500.55.68.1
  • kernel-syms SLE Module for Development Tools 15 SP5, openSUSE Leap 15.5 5.14.21-150500.55.68.1
  • kernel-obs-qa openSUSE Leap 15.5 5.14.21-150500.55.68.1
  • kernel-source SLE Module for Development Tools 15 SP5, SLE Module for Basesystem 15 SP5, openSUSE Leap 15.5 5.14.21-150500.55.68.1
  • kernel-default SLE Workstation Extension 15 SP5, SLE Module for Legacy 15 SP5, SLE Module for Basesystem 15 SP5 +4 more 5.14.21-150500.55.68.1
  • kernel-kvmsmall openSUSE Leap 15.5 5.14.21-150500.55.68.1
  • kernel-zfcpdump SLE Module for Basesystem 15 SP5, openSUSE Leap 15.5 5.14.21-150500.55.68.1

suse advisories SUSE-SU-2024:2190-1SUSE-SU-2024:2189-1SUSE-SU-2024:2185-1SUSE-SU-2024:2184-1SUSE-SU-2024:2183-1SUSE-SU-2024:2019-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-47424 updated cvss 4.4

kernel: i40e: Fix freeing of uninitialized misc IRQ vector

  • Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more
    affected: no fix available “Fix deferred”
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.22% chance of exploitation in the next 30 days, higher than 12% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Weakness
  • CWE-908 Use of Uninitialized Resource
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.