NVD / CVE Program· CNA Linux

CVE-2022-49626: sfc: fix use after free when disabling sriov

Noroxi assessment

Priority: Monitor (action score 31/100)

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: 0.27% (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 3199e34912d84cdfb8a93a984c5ae5c73fb13e84, 58d93e9d160c0de6d867c7eb4c2206671a351eb1, 9c854ae512b89229aeee93849e9bd4c115b37909.

Low priority for now. Upgrade to Linux Linux 3199e34912d84cdfb8a93a984c5ae5c73fb13e84, 58d93e9d160c0de6d867c7eb4c2206671a351eb1, 9c854ae512b89229aeee93849e9bd4c115b37909 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: sfc: fix use after free when disabling sriov Use after free is detected by kfence when disabling sriov. What was read after being freed was vf->pci_dev: it was freed from pci_disable_sriov and later read in efx_ef10_sriov_free_vf_vports, called from efx_ef10_sriov_free_vf_vswitching. Set the pointer to NULL at release time to not trying to read it later. Reproducer and dmesg log (note that kfence doesn't detect it every time): $ echo 1 > /sys/class/net/enp65s0f0np0/device/sriov_numvfs $ echo 0 > /sys/class/net/enp65s0f0np0/device/sriov_numvfs BUG: KFENCE: use-after-free read in efx_ef10_sriov_free_vf_vswitching+0x82/0x170 [sfc] Use-after-free read at 0x00000000ff3c1ba5 (in kfence-#224): efx_ef10_sriov_free_vf_vswitching+0x82/0x170 [sfc] efx_ef10_pci_sriov_disable+0x38/0x70 [sfc] efx_pci_sriov_configure+0x24/0x40 [sfc] sriov_numvfs_store+0xfe/0x140 kernfs_fop_write_iter+0x11c/0x1b0 new_sync_write+0x11f/0x1b0 vfs_write+0x1eb/0x280 ksys_write+0x5f/0xe0 do_syscall_64+0x5c/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae kfence-#224: 0x00000000edb8ef95-0x00000000671f5ce1, size=2792, cache=kmalloc-4k allocated by task 6771 on cpu 10 at 3137.860196s: pci_alloc_dev+0x21/0x60 pci_iov_add_virtfn+0x2a2/0x320 sriov_enable+0x212/0x3e0 efx_ef10_sriov_configure+0x67/0x80 [sfc] efx_pci_sriov_configure+0x24/0x40 [sfc] sriov_numvfs_store+0xba/0x140 kernfs_fop_write_iter+0x11c/0x1b0 new_sync_write+0x11f/0x1b0 vfs_write+0x1eb/0x280 ksys_write+0x5f/0xe0 do_syscall_64+0x5c/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae freed by task 6771 on cpu 12 at 3170.991309s: device_release+0x34/0x90 kobject_cleanup+0x3a/0x130 pci_iov_remove_virtfn+0xd9/0x120 sriov_disable+0x30/0xe0 efx_ef10_pci_sriov_disable+0x57/0x70 [sfc] efx_pci_sriov_configure+0x24/0x40 [sfc] sriov_numvfs_store+0xfe/0x140 kernfs_fop_write_iter+0x11c/0x1b0 new_sync_write+0x11f/0x1b0 vfs_write+0x1eb/0x280 ksys_write+0x5f/0xe0 do_syscall_64+0x5c/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae

HighCVSS 7.8 · v3.1—No exploit Fix available

Memory safety

BDU:2025-04422

Published: Feb 26, 2025
Updated: Jun 17, 2026
EPSS: 0.2% · 20th percentile
CWE: CWE-416

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 31 / 40 · 7.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.2%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

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 kernel4.2 and later · before 4.9.324
linux linux kernel4.10 and later · before 4.14.289
linux linux kernel4.15 and later · before 4.19.253
linux linux kernel4.20 and later · before 5.4.207
linux linux kernel5.5 and later · before 5.10.132
linux linux kernel5.11 and later · before 5.15.56
linux linux kernel5.16 and later · before 5.18.13
linux linux kernel5.19

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
- 4.2affected
- 3c5eb87605e85146a78de589b5070a37862425db and later · before 3199e34912d84cdfb8a93a984c5ae5c73fb13e84affected · git
- 3c5eb87605e85146a78de589b5070a37862425db and later · before c9e75bb22a26e391f189f5a5133dd63dcb57fdaaaffected · git
- 3c5eb87605e85146a78de589b5070a37862425db and later · before 9c854ae512b89229aeee93849e9bd4c115b37909affected · git
- 3c5eb87605e85146a78de589b5070a37862425db and later · before bcad880865bfb421885364b1f0c7351280fe2b97affected · git
- 3c5eb87605e85146a78de589b5070a37862425db and later · before c2240500817b3b4b996cdf2a461a3a5679f49b94affected · git
- 3c5eb87605e85146a78de589b5070a37862425db and later · before 58d93e9d160c0de6d867c7eb4c2206671a351eb1affected · git
- 3c5eb87605e85146a78de589b5070a37862425db and later · before e435c4aeeaa073091f7f3b7735af2ef5c97d63f2affected · git
- 3c5eb87605e85146a78de589b5070a37862425db and later · before ebe41da5d47ac0fff877e57bd14c54dccf168827affected · git
- before 4.2not affected · semver

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 5.18.14-1	5.18.14-1

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-2022-49623Feb 26, 2025 · powerpc/xive/spapr: correct bitmap allocation size
28Monitor
← EarlierCVE-2022-49625Feb 26, 2025 · sfc: fix kernel panic when creating VF
22Monitor
Later →CVE-2022-49627Feb 26, 2025 · ima: Fix potential memory leak in ima_init_crypto()
22Monitor

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	3199e34912d84cdfb8a93a984c5ae5c73fb13e84	Vendor (CNA)
Linux Linux	58d93e9d160c0de6d867c7eb4c2206671a351eb1	Vendor (CNA)
Linux Linux	9c854ae512b89229aeee93849e9bd4c115b37909	Vendor (CNA)
Linux Linux	bcad880865bfb421885364b1f0c7351280fe2b97	Vendor (CNA)
Linux Linux	c2240500817b3b4b996cdf2a461a3a5679f49b94	Vendor (CNA)
Linux Linux	c9e75bb22a26e391f189f5a5133dd63dcb57fdaa	Vendor (CNA)
Linux Linux	e435c4aeeaa073091f7f3b7735af2ef5c97d63f2	Vendor (CNA)
Linux Linux	ebe41da5d47ac0fff877e57bd14c54dccf168827	Vendor (CNA)
debian:linux	5.18.14-1 · 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.

No nightly-computed relations.

Chain candidates

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

—

Bug bounty scope

No known public program.

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

Technical details

Attack conditions

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.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Attack vector: Local
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-secondary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

Fix✗ → ✓Sep 28, 2026, 10:10 PM UTC

For records you follow, these changes also arrive as notifications. →

References

git.kernel.org/stable/c/3199e34912d84cdfb8a93a984c5ae5c73fb13e84

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records