# CVE-2021-47424: linux: In the Linux kernel, the following vulnerability has been resolved:  i40e: Fix freeing of uninitialized misc IRQ vect...

CVE-2021-47424 is fixed in linux on 1 platform, first by DEBIAN-CVE-2021-47424, released May 21, 2024. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2021-47424
- Priority: Routine
- CVSS: 5.5 (medium)
- EPSS: 0.0022
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: May 21, 2024

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 12.15 (bookworm) | 5.14.12-1 | [DEBIAN-CVE-2021-47424](https://patchblox.com/security/data/fix/linux/debian-cve-2021-47424.md) | May 21, 2024 |
| Linux | linux Debian 13.5 (trixie) | 5.14.12-1 | [DEBIAN-CVE-2021-47424](https://patchblox.com/security/data/fix/linux/debian-cve-2021-47424.md) | May 21, 2024 |
| Linux | linux Debian 14 | 5.14.12-1 | [DEBIAN-CVE-2021-47424](https://patchblox.com/security/data/fix/linux/debian-cve-2021-47424.md) | May 21, 2024 |

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