NVD / CVE Program· CNA Linux

CVE-2022-49761: btrfs: always report error in run_one_delayed_ref()

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: 0.19% (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 18bd1c9c02e64a3567f90c83c2c8b855531c8098, 39f501d68ec1ed5cd5c66ac6ec2a7131c517bb92, 853ffa1511b058c79a4c9bb1407b3b20ce311792.

Low priority for now. Upgrade to Linux Linux 18bd1c9c02e64a3567f90c83c2c8b855531c8098, 39f501d68ec1ed5cd5c66ac6ec2a7131c517bb92, 853ffa1511b058c79a4c9bb1407b3b20ce311792 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: btrfs: always report error in run_one_delayed_ref() Currently we have a btrfs_debug() for run_one_delayed_ref() failure, but if end users hit such problem, there will be no chance that btrfs_debug() is enabled. This can lead to very little useful info for debugging. This patch will: - Add extra info for error reporting Including: * logical bytenr * num_bytes * type * action * ref_mod - Replace the btrfs_debug() with btrfs_err() - Move the error reporting into run_one_delayed_ref() This is to avoid use-after-free, the @node can be freed in the caller. This error should only be triggered at most once. As if run_one_delayed_ref() failed, we trigger the error message, then causing the call chain to error out: btrfs_run_delayed_refs() `- btrfs_run_delayed_refs() `- btrfs_run_delayed_refs_for_head() `- run_one_delayed_ref() And we will abort the current transaction in btrfs_run_delayed_refs(). If we have to run delayed refs for the abort transaction, run_one_delayed_ref() will just cleanup the refs and do nothing, thus no new error messages would be output.

HighCVSS 7.8 · v3.1—No exploit Fix available

Memory safety

BDU:2025-06308

Published: Mar 27, 2025
Updated: Jun 17, 2026
EPSS: 0.1% · 9th 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 · 0.1%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: total

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?

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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 5.10.165
linux linux kernel5.11 and later · before 5.15.90
linux linux kernel5.16 and later · before 6.1.8
linux linux kernel6.2

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
- 3.4affected
- 79787eaab46121d4713ed03c8fc63b9ec3eaec76 and later · before 18bd1c9c02e64a3567f90c83c2c8b855531c8098affected · git
- 79787eaab46121d4713ed03c8fc63b9ec3eaec76 and later · before fdb4a70bb768d2a87890409597529ad81cb3de8aaffected · git
- 79787eaab46121d4713ed03c8fc63b9ec3eaec76 and later · before 853ffa1511b058c79a4c9bb1407b3b20ce311792affected · git
- 79787eaab46121d4713ed03c8fc63b9ec3eaec76 and later · before 39f501d68ec1ed5cd5c66ac6ec2a7131c517bb92affected · git
- before 3.4not affected · semver
- 5.10.165 and later · up to and including 5.10.*not affected · semver
- 5.15.90 and later · up to and including 5.15.*not affected · semver
- 6.1.8 and later · up to and including 6.1.*not affected · semver
- 6.2 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 6.1.8-1	6.1.8-1

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-2022-49758Mar 27, 2025 · reset: uniphier-glue: Fix possible null-ptr-deref
22Monitor
← EarlierCVE-2022-49759Mar 27, 2025 · VMCI: Use threaded irqs instead of tasklets
22Monitor
Later →CVE-2023-52929Mar 27, 2025 · nvmem: core: fix cleanup after dev_set_name()
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	18bd1c9c02e64a3567f90c83c2c8b855531c8098	Vendor (CNA)
Linux Linux	39f501d68ec1ed5cd5c66ac6ec2a7131c517bb92	Vendor (CNA)
Linux Linux	853ffa1511b058c79a4c9bb1407b3b20ce311792	Vendor (CNA)
Linux Linux	fdb4a70bb768d2a87890409597529ad81cb3de8a	Vendor (CNA)
debian:linux	6.1.8-1 · 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, 10:11 PM UTC

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

References

git.kernel.org/stable/c/18bd1c9c02e64a3567f90c83c2c8b855531c8098

Show all references (3 more)

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

All records