CVE-2022-49174

Kernel crash via stale block-group bitmap reuse

Published Feb 26, 2025 · Updated Aug 5, 2026

Out-of-bounds memory access in Linux ext4 allows local users to crash the kernel by mounting a crafted fast-commit image. During journal replay, ext4_mb_mark_bb() retains the starting block group's bitmap buffer when an extent crosses into another group, so its bit loop accesses memory beyond bitmap_bh->b_data. Reachability requires a local mount path and an ext4 image with flex_bg and fast_commit metadata spanning block groups; the observed result is a data-access abort.

CVSS severity7.8
High
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds memory access in Linux ext4 allows local users to crash the kernel by mounting a crafted fast-commit image. During journal replay, ext4_mb_mark_bb() retains the starting block group's bitmap buffer when an extent crosses into another group, so its bit loop accesses memory beyond bitmap_bh->b_data. Reachability requires a local mount path and an ext4 image with flex_bg and fast_commit metadata spanning block groups; the observed result is a data-access abort.

The record

CVE
CVE-2022-49174
Published
Feb 26, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
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=5.10
  2. Affected versionversion=8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2 <6a6beb074186a0452368a023a261c7d0eaebe838
  3. Affected versionversion=8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2 <803fb0e8240cc16585a5c9df76add1dfaa781773
  4. Affected versionversion=8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2 <b07eedd0222e9548ffc568ec429bb1f61d21a39c
  5. Affected versionversion=8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2 <bfdc502a4a4c058bf4cbb1df0c297761d528f54d
  6. Affected versionversion=8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2 <cd6d719534af993210306f8a13f9cb3e615f7c8d

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.10; version=8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2 <6a6beb074186a0452368a023a261c7d0eaebe838; version=8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2 <803fb0e8240cc16585a5c9df76add1dfaa781773; version=8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2 <b07eedd0222e9548ffc568ec429bb1f61d21a39c; version=8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2 <bfdc502a4a4c058bf4cbb1df0c297761d528f54d; version=8016e29f4362e285f0f7e38fadc61a5b7bdfdfa2 <cd6d719534af993210306f8a13f9cb3e615f7c8d

Published CVSS scores

5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
6.8SUSECVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
5.5SUSECVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.8Linux Kernel CNACVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

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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