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NVD / CVE Program· CNA Linux

CVE-2022-49300: nbd: fix race between nbd_alloc_config() and module removal

Noroxi assessment

Priority: Monitor (action score 18/100)

  • 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. Special conditions such as timing or configuration are required.
  • Fixed version: Linux Linux 122e4adaff2439f1cc18cc7e931980fa7560df5c, 165cf2e0019fa6cedc75b456490c41494c34abb4, 2573f2375b64280be977431701ed5d33b75b9ad0.

Low priority for now. Upgrade to Linux Linux 122e4adaff2439f1cc18cc7e931980fa7560df5c, 165cf2e0019fa6cedc75b456490c41494c34abb4, 2573f2375b64280be977431701ed5d33b75b9ad0 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: nbd: fix race between nbd_alloc_config() and module removal When nbd module is being removing, nbd_alloc_config() may be called concurrently by nbd_genl_connect(), although try_module_get() will return false, but nbd_alloc_config() doesn't handle it. The race may lead to the leak of nbd_config and its related resources (e.g, recv_workq) and oops in nbd_read_stat() due to the unload of nbd module as shown below: BUG: kernel NULL pointer dereference, address: 0000000000000040 Oops: 0000 [#1] SMP PTI CPU: 5 PID: 13840 Comm: kworker/u17:33 Not tainted 5.14.0+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) Workqueue: knbd16-recv recv_work [nbd] RIP: 0010:nbd_read_stat.cold+0x130/0x1a4 [nbd] Call Trace: recv_work+0x3b/0xb0 [nbd] process_one_work+0x1ed/0x390 worker_thread+0x4a/0x3d0 kthread+0x12a/0x150 ret_from_fork+0x22/0x30 Fixing it by checking the return value of try_module_get() in nbd_alloc_config(). As nbd_alloc_config() may return ERR_PTR(-ENODEV), assign nbd->config only when nbd_alloc_config() succeeds to ensure the value of nbd->config is binary (valid or NULL). Also adding a debug message to check the reference counter of nbd_config during module removal.

MediumCVSS 4.7 · v3.1—No exploit Fix available
Published
Feb 26, 2025
Updated
Jun 17, 2026
EPSS
0.1% · 8th percentile

Report tools

JSON

Action score

18

Monitor

Low priority for now.

CVSS
18 / 40 · 4.7 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

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

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

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  • when exploit code appears or is weaponized
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  • when EPSS rises 20 points in a week

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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.

VendorProduct
linuxlinux 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 4.14.283
  • linux linux kernel4.15 and later · before 4.19.247
  • linux linux kernel4.20 and later · before 5.4.198
  • linux linux kernel5.5 and later · before 5.10.122
  • linux linux kernel5.11 and later · before 5.15.47
  • linux linux kernel5.16 and later · before 5.17.15
  • linux linux kernel5.18 and later · before 5.18.4

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

    • 4.12affected
    • 5ea8d10802ec4c153a6e21eebaf412e2abd29736 and later · before 165cf2e0019fa6cedc75b456490c41494c34abb4affected · git
    • 5ea8d10802ec4c153a6e21eebaf412e2abd29736 and later · before 2573f2375b64280be977431701ed5d33b75b9ad0affected · git
    • 5ea8d10802ec4c153a6e21eebaf412e2abd29736 and later · before 8a7da4ced236ce6637fe70f14ca18e718d4bf9e9affected · git
    • 5ea8d10802ec4c153a6e21eebaf412e2abd29736 and later · before 122e4adaff2439f1cc18cc7e931980fa7560df5caffected · git
    • 5ea8d10802ec4c153a6e21eebaf412e2abd29736 and later · before 71c142f910da44421213ade601bcbd23ceae19faaffected · git
    • 5ea8d10802ec4c153a6e21eebaf412e2abd29736 and later · before 2888fa41985f93ed0a6837cfbb06bcbfd7fa2314affected · git
    • 5ea8d10802ec4c153a6e21eebaf412e2abd29736 and later · before d09525720dd5201756f698bee1076de9aefd4602affected · git
    • 5ea8d10802ec4c153a6e21eebaf412e2abd29736 and later · before c55b2b983b0fa012942c3eb16384b2b722caa810affected · git
    • before 4.12not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 5.18.5-15.18.5-1

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-2022-49297Feb 26, 2025 · nbd: fix io hung while disconnecting device
    22Monitor
  • ← EarlierCVE-2022-49298Feb 26, 2025 · staging: rtl8712: fix uninit-value in r871xu_drv_init()
    22Monitor
  • Later →CVE-2022-49301Feb 26, 2025 · staging: rtl8712: fix uninit-value in usb_read8() and friends
    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 / packageFixed versionSource
Linux Linux122e4adaff2439f1cc18cc7e931980fa7560df5cVendor (CNA)
Linux Linux165cf2e0019fa6cedc75b456490c41494c34abb4Vendor (CNA)
Linux Linux2573f2375b64280be977431701ed5d33b75b9ad0Vendor (CNA)
Linux Linux2888fa41985f93ed0a6837cfbb06bcbfd7fa2314Vendor (CNA)
Linux Linux71c142f910da44421213ade601bcbd23ceae19faVendor (CNA)
Linux Linux8a7da4ced236ce6637fe70f14ca18e718d4bf9e9Vendor (CNA)
Linux Linuxc55b2b983b0fa012942c3eb16384b2b722caa810Vendor (CNA)
Linux Linuxd09525720dd5201756f698bee1076de9aefd4602Vendor (CNA)
debian:linux5.18.5-1 · Debian:12Package 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.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
High
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-362 · Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSS vector

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

nvd-primary

Attack context

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

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

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

References

Show all references (7 more)

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

All records