CVE-2024-49854

Local privilege escalation via BFQ queue use-after-free

Published Oct 21, 2024 · Updated Aug 5, 2026

Use-after-free in the Linux BFQ I/O scheduler allows local users to escalate privileges through ordinary filesystem I/O. In bfq_split_bfqq(), the last holder can release a bfq_queue before code dereferences its waker_bfqq pointer, and a linked waker can share the same merge chain. When BFQ services the attacker's block queue, the stale access enables kernel-memory corruption, a kernel panic, or privilege escalation without user interaction.

CVSS severity7.8
High
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in the Linux BFQ I/O scheduler allows local users to escalate privileges through ordinary filesystem I/O. In bfq_split_bfqq(), the last holder can release a bfq_queue before code dereferences its waker_bfqq pointer, and a linked waker can share the same merge chain. When BFQ services the attacker's block queue, the stale access enables kernel-memory corruption, a kernel panic, or privilege escalation without user interaction.

The record

CVE
CVE-2024-49854
Published
Oct 21, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-416, T1068
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Oct 21, 2024CVE 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=13b3d0e8cb121f99b11918a0d4bcc1ce4647d352 <0b8bda0ff17156cd3f60944527c9d8c9f99f1583
  2. Affected versionversion=19f3bec2ac4be329b9bd12b18a989b867618d2d8 <0780451f03bf518bc032a7c584de8f92e2d39d7f
  3. Affected versionversion=3630a18846c7853aa326d3b42fd0a855af7b41bc
  4. Affected versionversion=3a5f45a4ad4e1fd36b0a998eef03d76a4f02a2a8
  5. Affected versionversion=4.19.323 <4.20
  6. Affected versionversion=42c306ed723321af4003b2a41bb73728cab54f85 <1ba0403ac6447f2d63914fb760c44a3b19c44eaf
  7. Affected versionversion=4780f50ea50cfe8e89fc3747bf3dd155488433bb <cae58d19121a70329cf971359e2518c93fec04fe
  8. Affected versionversion=5.10.227 <5.11
  9. Affected versionversion=5.4.285 <5.5
  10. Affected versionversion=9e813033594b141f61ff0ef0cfaaef292564b041
  11. Affected versionversion=de6c5e3a456019d2182e345730e59721714fa0b5 <de0456460f2abf921e356ed2bd8da87a376680bd
  12. Affected versionversion=e0c20d88b7dce85d2703bb6ba77bf359959675cd <63a07379fdb6c72450cb05294461c6016b8b7726

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=13b3d0e8cb121f99b11918a0d4bcc1ce4647d352 <0b8bda0ff17156cd3f60944527c9d8c9f99f1583; version=19f3bec2ac4be329b9bd12b18a989b867618d2d8 <0780451f03bf518bc032a7c584de8f92e2d39d7f; version=3630a18846c7853aa326d3b42fd0a855af7b41bc; version=3a5f45a4ad4e1fd36b0a998eef03d76a4f02a2a8; version=4.19.323 <4.20; version=42c306ed723321af4003b2a41bb73728cab54f85 <1ba0403ac6447f2d63914fb760c44a3b19c44eaf; version=4780f50ea50cfe8e89fc3747bf3dd155488433bb <cae58d19121a70329cf971359e2518c93fec04fe; version=5.10.227 <5.11; version=5.4.285 <5.5; version=9e813033594b141f61ff0ef0cfaaef292564b041; version=de6c5e3a456019d2182e345730e59721714fa0b5 <de0456460f2abf921e356ed2bd8da87a376680bd; version=e0c20d88b7dce85d2703bb6ba77bf359959675cd <63a07379fdb6c72450cb05294461c6016b8b7726

Published CVSS scores

7.8CISA ADPCVSS: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

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

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1068Exploitation for Privilege Escalation

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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