CVE-2021-47424: i40e: Fix freeing of uninitialized misc IRQ vector
Vulnerability summary
CVE-2021-47424 is a medium (CVSS 5.5) Use of Uninitialized Resource vulnerability in linux. EPSS estimates a 0.22% chance of exploitation in the next 30 days, higher than 12.9% of scored vulnerabilities.
Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 11 · Related 11Timeline
- 21-05-2024PublishedVulnerability first disclosed.
- 11-05-2026Last modifiedVulnerability information updated.
Description
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.
CVSS metrics
3 scores · 3 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.22%
Chance of exploitation in the next 30 days
Percentile
13%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.22% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu86 products
- linux< 4.15.0-166.174 | < 5.4.0-92.103
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 4.15.0-1118.125 | < 5.4.0-1061.64
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ c17401a1dd210a5f22ab1ec7c7366037c158a14c, < 60ad4cde0ad28921f9ea25b0201c774b95ffa4b4 | ≥ c17401a1dd210a5f22ab1ec7c7366037c158a14c, < 17063cac4088b8e2fc0f633abddca5426ed58312 | ≥ c17401a1dd210a5f22ab1ec7c7366037c158a14c, < 97aeed72af4f83ae51534f0a2473ff52f8d66236 | ≥ c17401a1dd210a5f22ab1ec7c7366037c158a14c, < 75099439209d3cda439a1d9b00d19a50f0066fef | ≥ c17401a1dd210a5f22ab1ec7c7366037c158a14c, < 2e5a20573a926302b233b0c2e1077f5debc7ab2e | 4.15
- linux_kernel≥ 4.15, < 4.19.211 | ≥ 4.20, < 5.4.153 | ≥ 5.5, < 5.10.73 | ≥ 5.11, < 5.14.12 | 5.15:rc1 | 5.15:rc2 | 5.15:rc3 | 5.15:rc4
Debian1 product
- linux< 5.14.12-1
3 vendors · 89 products
