CVE-2022-49075Network attack vector

Quota bypass via 32-bit reservation counter overflow

Published Feb 26, 2025 · Updated Aug 5, 2026

Integer overflow in Btrfs qgroup reservation in Linux allows remote authenticated users to bypass configured storage quotas. The qgroup_reserve_data() path stores extent_changeset->bytes_changed as a 32-bit unsigned integer, so a fallocate range larger than 4 GiB wraps the reservation count and reserves too few bytes. A writable Btrfs volume with qgroups enabled is required; the bypass permits allocations beyond the assigned limit and can exhaust shared space.

CVSS severity8.1
High
EPSS probability0.66%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer overflow in Btrfs qgroup reservation in Linux allows remote authenticated users to bypass configured storage quotas. The qgroup_reserve_data() path stores extent_changeset->bytes_changed as a 32-bit unsigned integer, so a fallocate range larger than 4 GiB wraps the reservation count and reserves too few bytes. A writable Btrfs volume with qgroups enabled is required; the bypass permits allocations beyond the assigned limit and can exhaust shared space.

The record

CVE
CVE-2022-49075
Published
Feb 26, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-190, T1499
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 26, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.13
  2. Affected versionversion=7bc329c1836866ffac8b2613f780a51b3ffe786d <0355387ea5b02d353c9415613fab908fac5c52a6
  3. Affected versionversion=7bc329c1836866ffac8b2613f780a51b3ffe786d <44277c50fdba5019ca25bfad1b71e2561b0de11b
  4. Affected versionversion=7bc329c1836866ffac8b2613f780a51b3ffe786d <4b98799e181b4326a613108cf37acc1f55d21b45
  5. Affected versionversion=7bc329c1836866ffac8b2613f780a51b3ffe786d <6bfff81286d4491f02dad7814bae5c77c9ad2320
  6. Affected versionversion=7bc329c1836866ffac8b2613f780a51b3ffe786d <7941b74ed49b6db25efbef2256ebef843c11a010
  7. Affected versionversion=7bc329c1836866ffac8b2613f780a51b3ffe786d <82ae73ac963cee877ce34f7c31b2b456b516e96c
  8. Affected versionversion=7bc329c1836866ffac8b2613f780a51b3ffe786d <b642b52d0b50f4d398cb4293f64992d0eed2e2ce
  9. Affected versionversion=7bc329c1836866ffac8b2613f780a51b3ffe786d <f3d97b22a708bf9e3f3ac2ba232bcefd0b0c136b

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.13; version=7bc329c1836866ffac8b2613f780a51b3ffe786d <0355387ea5b02d353c9415613fab908fac5c52a6; version=7bc329c1836866ffac8b2613f780a51b3ffe786d <44277c50fdba5019ca25bfad1b71e2561b0de11b; version=7bc329c1836866ffac8b2613f780a51b3ffe786d <4b98799e181b4326a613108cf37acc1f55d21b45; version=7bc329c1836866ffac8b2613f780a51b3ffe786d <6bfff81286d4491f02dad7814bae5c77c9ad2320; version=7bc329c1836866ffac8b2613f780a51b3ffe786d <7941b74ed49b6db25efbef2256ebef843c11a010; version=7bc329c1836866ffac8b2613f780a51b3ffe786d <82ae73ac963cee877ce34f7c31b2b456b516e96c; version=7bc329c1836866ffac8b2613f780a51b3ffe786d <b642b52d0b50f4d398cb4293f64992d0eed2e2ce; version=7bc329c1836866ffac8b2613f780a51b3ffe786d <f3d97b22a708bf9e3f3ac2ba232bcefd0b0c136b

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
8.1kernel.orgCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-190Integer Overflow or Wraparound
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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