Use-after-free via double-counted DMA channel references
Published Mar 27, 2025 · Updated May 11, 2026
Use-after-free in affected Linux kernel dmaengine branches from 4.0 allows local users to corrupt DMA channel resource accounting. dma_chan_get() increments client_count once in balance_ref_count() and again before returning for a public channel, so later releases fail to free resources at the correct time. Repeated async_tx module load and unload produced retained channel references, a kref underflow, and a use-after-free warning; module lifecycle access is required.
Summary
What happened
Use-after-free in affected Linux kernel dmaengine branches from 4.0 allows local users to corrupt DMA channel resource accounting. dma_chan_get() increments client_count once in balance_ref_count() and again before returning for a public channel, so later releases fail to free resources at the correct time. Repeated async_tx module load and unload produced retained channel references, a kref underflow, and a use-after-free warning; module lifecycle access is required.
The record
- CVE
- CVE-2022-49753
- Published
- Mar 27, 2025
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-416
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Mar 27, 2025CVE publishedPublication date reported by the CVE source.
- May 11, 2026Record updatedLatest update available in the CVE record.
Exploitability
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Is a vulnerable build present?
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- Affected versionversion=4.0
- Affected versionversion=d2f4f99db3e9ec8b063cf2e45704e2bb95428317 <142d644fd2cc059ffa042fbfb68e766433ef3afd
- Affected versionversion=d2f4f99db3e9ec8b063cf2e45704e2bb95428317 <18dd3b30d4c7e8440c63118c7a7b687372b9567f
- Affected versionversion=d2f4f99db3e9ec8b063cf2e45704e2bb95428317 <1b409e14b4b7af034e0450f95c165b6c5c87dbc1
- Affected versionversion=d2f4f99db3e9ec8b063cf2e45704e2bb95428317 <42ecd72f02cd657b00b559621e7ef7d2c4d3e5f1
- Affected versionversion=d2f4f99db3e9ec8b063cf2e45704e2bb95428317 <71c601965532c38030133535f7cd93c1efa75af1
- Affected versionversion=d2f4f99db3e9ec8b063cf2e45704e2bb95428317 <c6221afe573413fd2981e291f7df4a58283e0654
- Affected versionversion=d2f4f99db3e9ec8b063cf2e45704e2bb95428317 <f3dc1b3b4750851a94212dba249703dd0e50bb20
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What is affected?
Published CVSS scores
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Attacks
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