NVD / CVE Program· CNA Linux

CVE-2021-47283: net:sfc: fix non-freed irq in legacy irq mode

Noroxi assessment

Priority: Monitor (action score 22/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.22% (FIRST EPSS).
Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
Fixed version: Linux Linux 81c4d1d83f88e15b26f4522a35cba6ffd8c5dfdd, 8d717c9135a3340ae62d1699484850bfb4112b0c, 8f03eeb6e0a0a0b8d617ee0a4bce729e47130036.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 81c4d1d83f88e15b26f4522a35cba6ffd8c5dfdd, 8d717c9135a3340ae62d1699484850bfb4112b0c, 8f03eeb6e0a0a0b8d617ee0a4bce729e47130036 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: net:sfc: fix non-freed irq in legacy irq mode SFC driver can be configured via modparam to work using MSI-X, MSI or legacy IRQ interrupts. In the last one, the interrupt was not properly released on module remove. It was not freed because the flag irqs_hooked was not set during initialization in the case of using legacy IRQ. Example of (trimmed) trace during module remove without this fix: remove_proc_entry: removing non-empty directory 'irq/125', leaking at least '0000:3b:00.1' WARNING: CPU: 39 PID: 3658 at fs/proc/generic.c:715 remove_proc_entry+0x15c/0x170 ...trimmed... Call Trace: unregister_irq_proc+0xe3/0x100 free_desc+0x29/0x70 irq_free_descs+0x47/0x70 mp_unmap_irq+0x58/0x60 acpi_unregister_gsi_ioapic+0x2a/0x40 acpi_pci_irq_disable+0x78/0xb0 pci_disable_device+0xd1/0x100 efx_pci_remove+0xa1/0x1e0 [sfc] pci_device_remove+0x38/0xa0 __device_release_driver+0x177/0x230 driver_detach+0xcb/0x110 bus_remove_driver+0x58/0xd0 pci_unregister_driver+0x2a/0xb0 efx_exit_module+0x24/0xf40 [sfc] __do_sys_delete_module.constprop.0+0x171/0x280 ? exit_to_user_mode_prepare+0x83/0x1d0 do_syscall_64+0x3d/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f9f9385800b ...trimmed...

MediumCVSS 5.5 · v3.1—No exploit Fix available

Denial of service

BDU:2025-07386

Published: May 21, 2024
Updated: Jun 17, 2026
EPSS: 0.2% · 12th percentile
CWE: CWE-772

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 22 / 40 · 5.5 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.2%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

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Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
linux	linux kernel	cpe:2.3:o:linux:linux_kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

linux linux kernelbefore 5.10.44
linux linux kernel5.11 and later · before 5.12.11
linux linux kernel5.13

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

Linux Linux
- 5.9affected
- e6a43910d55d09dae65772ad571d4c61e459b17a and later · before 8d717c9135a3340ae62d1699484850bfb4112b0caffected · git
- e6a43910d55d09dae65772ad571d4c61e459b17a and later · before 81c4d1d83f88e15b26f4522a35cba6ffd8c5dfddaffected · git
- e6a43910d55d09dae65772ad571d4c61e459b17a and later · before 8f03eeb6e0a0a0b8d617ee0a4bce729e47130036affected · git
- before 5.9not affected · semver
- 5.10.44 and later · up to and including 5.10.*not affected · semver
- 5.12.11 and later · up to and including 5.12.*not affected · semver
- 5.13 and laternot affected · original_commit_for_fix

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Debian:12	linux	before 5.10.46-1	5.10.46-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
90Now
CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
89Now
CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
85Now

Published before and after this one in the same product

← EarlierCVE-2021-47281May 21, 2024 · ALSA: seq: Fix race of snd_seq_timer_open()
28Monitor
← EarlierCVE-2021-47282May 21, 2024 · spi: bcm2835: Fix out-of-bounds access with more than 4 slaves
31Monitor
Later →CVE-2021-47284May 21, 2024 · isdn: mISDN: netjet: Fix crash in nj_probe:
18Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
Linux Linux	81c4d1d83f88e15b26f4522a35cba6ffd8c5dfdd	Vendor (CNA)
Linux Linux	8d717c9135a3340ae62d1699484850bfb4112b0c	Vendor (CNA)
Linux Linux	8f03eeb6e0a0a0b8d617ee0a4bce729e47130036	Vendor (CNA)
debian:linux	5.10.46-1 · Debian:12	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

CVE-2022-50189393 days aparttools/power turbostat: Fix file pointer leak
28Monitor
CVE-2024-358214 days apartubifs: Set page uptodate in the correct place
22Monitor
CVE-2024-47733153 days apartnetfs: Delete subtree of 'fs/netfs' when netfs module exits
22Monitor
CVE-2024-53074182 days apartwifi: iwlwifi: mvm: don't leak a link on AP removal
22Monitor
CVE-2023-22996448 days apartIn the Linux kernel before 5.17.2, drivers/soc/qcom/qcom_aoss.c does not release an of_find_device_by_node reference after use, e.g., with p
22Monitor
CVE-2023-53199482 days apartwifi: ath9k: hif_usb: clean up skbs if ath9k_hif_usb_rx_stream() fails
22Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

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Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).