Console output loop via DMA and PIO race
Published Sep 4, 2026 · Updated Sep 4, 2026
Race condition in Linux kernel msm serial consoles since 4.4 allows local users with TTY write access to cause endless console output. In msm_startup, console UARTs use DMA, allowing a userspace DMA transfer to overlap printk reconfiguration of the controller for PIO without awaiting DMA completion. The race requires an MSM UARTDM console and concurrent userspace and kernel writes; zero DMA progress repeatedly prints the same text and disrupts console availability.
Summary
What happened
Race condition in Linux kernel msm serial consoles since 4.4 allows local users with TTY write access to cause endless console output. In msm_startup, console UARTs use DMA, allowing a userspace DMA transfer to overlap printk reconfiguration of the controller for PIO without awaiting DMA completion. The race requires an MSM UARTDM console and concurrent userspace and kernel writes; zero DMA progress repeatedly prints the same text and disrupts console availability.
The record
- CVE
- CVE-2026-80886
- Published
- Sep 4, 2026
- Updated
- Sep 4, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-362, T1499
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Sep 4, 2026CVE publishedPublication date reported by the CVE source.
- Sep 4, 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=3a878c430fd6eb4f8587f9ebd187f773bf85d1d6 <22dd2777e6c180e1c945b00f6d18550979436324
- Affected versionversion=3a878c430fd6eb4f8587f9ebd187f773bf85d1d6 <2727744ccb5ca59090451451ee94f530b1be04a5
- Affected versionversion=3a878c430fd6eb4f8587f9ebd187f773bf85d1d6 <6acea62738ed4cae6746483026706a773b44dad7
- Affected versionversion=3a878c430fd6eb4f8587f9ebd187f773bf85d1d6 <abc1926c88c189e5d698b91ed6890e09ab5c321d
- Affected versionversion=3a878c430fd6eb4f8587f9ebd187f773bf85d1d6 <bb4296de5b538b575978c588cb3738ab8524d01a
- Affected versionversion=3a878c430fd6eb4f8587f9ebd187f773bf85d1d6 <d354716245192de2d203f2b35f22ab8dc13595e2
- Affected versionversion=3a878c430fd6eb4f8587f9ebd187f773bf85d1d6 <e3b42e326f4f30efcdc90bad5f5ba37e1cd91a47
- Affected versionversion=3a878c430fd6eb4f8587f9ebd187f773bf85d1d6 <f58e568dc308c8e13f7730c8de2da5ed514e540d
- Affected versionversion=4.4
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
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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