Local privilege escalation via BFQ queue use-after-free
Published Feb 26, 2025 · Updated Aug 12, 2026
Use-after-free in the Linux BFQ I/O scheduler allows local users to gain kernel privileges through cgroup-associated block I/O. bfq_bfqq_move migrates the reserved oom_bfqq from the root group, breaking reference ownership so __bfq_put_async_bfqq writes through a freed bfq_group during queue teardown. A low-privilege local account must issue I/O on a BFQ-managed device and trigger cgroup association changes; successful exploitation corrupts kernel memory, while failed attempts can panic the host.
Summary
What happened
Use-after-free in the Linux BFQ I/O scheduler allows local users to gain kernel privileges through cgroup-associated block I/O. bfq_bfqq_move migrates the reserved oom_bfqq from the root group, breaking reference ownership so __bfq_put_async_bfqq writes through a freed bfq_group during queue teardown. A low-privilege local account must issue I/O on a BFQ-managed device and trigger cgroup association changes; successful exploitation corrupts kernel memory, while failed attempts can panic the host.
The record
- CVE
- CVE-2022-49179
- Published
- Feb 26, 2025
- Updated
- Aug 12, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-416, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 26, 2025CVE publishedPublication date reported by the CVE source.
- Aug 12, 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.
- Affected versionversion=0d52af590552473666da5b6111e7182d6cd23f92 <7507ead1e9d42957c2340f2c4a0e9d00034e3366
- Affected versionversion=0d52af590552473666da5b6111e7182d6cd23f92 <8410f70977734f21b8ed45c37e925d311dfda2e7
- Affected versionversion=0d52af590552473666da5b6111e7182d6cd23f92 <87fdfe8589d43e471dffb4c60f75eeb6f37afc4c
- Affected versionversion=0d52af590552473666da5b6111e7182d6cd23f92 <8f34dea99cd7761156a146a5258a67d045d862f7
- Affected versionversion=0d52af590552473666da5b6111e7182d6cd23f92 <c01fced8d38fbccc82787065229578006f28e020
- Affected versionversion=0d52af590552473666da5b6111e7182d6cd23f92 <c4f5a678add58a8a0e7ee5e038496b376ea6d205
- Affected versionversion=4.16
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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