System hang via unbounded transmitter-empty wait
Published Jul 12, 2024 · Updated May 23, 2026
Improper locking in the Linux i.MX serial driver allows local users to hang affected systems by keeping the transmitter nonempty. In drivers/tty/serial/imx.c, the console-write path polls USR2_TXDC without a timeout and can wait forever when the transmitter never reports empty. Local low-privileged access and an affected i.MX serial device are required; the bounded consequence is a kernel deadlock and service hang.
Summary
What happened
Improper locking in the Linux i.MX serial driver allows local users to hang affected systems by keeping the transmitter nonempty. In drivers/tty/serial/imx.c, the console-write path polls USR2_TXDC without a timeout and can wait forever when the transmitter never reports empty. Local low-privileged access and an affected i.MX serial device are required; the bounded consequence is a kernel deadlock and service hang.
The record
- CVE
- CVE-2024-40967
- Published
- Jul 12, 2024
- Updated
- May 23, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-667, T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 12, 2024CVE publishedPublication date reported by the CVE source.
- May 23, 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=3.2.30 <3.3
- Affected versionversion=3.4.12 <3.5
- Affected versionversion=34d4dda865d8174f4a437f313c457c42a8fa9535
- Affected versionversion=3.5.5 <3.6
- Affected versionversion=3.6
- Affected versionversion=86236252d2449313bdbac790023cbc957bf6e426
- Affected versionversion=9ec1882df244c4ee1baa692676fef5e8b0f5487d <53b2c95547427c358f45515a9f144efee95e3701
- Affected versionversion=9ec1882df244c4ee1baa692676fef5e8b0f5487d <7f2b9ab6d0b26f16cd38dd9fd91d51899635f7c7
- Affected versionversion=9ec1882df244c4ee1baa692676fef5e8b0f5487d <7f9e70c68b7ace0141fe3bc94bf7b61296b71916
- Affected versionversion=9ec1882df244c4ee1baa692676fef5e8b0f5487d <982ae3376c4c91590d38dc8a676c10f7df048a44
- Affected versionversion=9ec1882df244c4ee1baa692676fef5e8b0f5487d <e533e4c62e9993e62e947ae9bbec34e4c7ae81c2
- Affected versionversion=c096552004244868391b29f319ea8889d55abe19
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Public exploit references
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Technologies
Your stack
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Your stack
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