System freeze via I2C clock lock inversion
Published Aug 15, 2026 · Updated Aug 15, 2026
Deadlock in the Linux kernel jz4780 I2C driver from 4.1 allows attackers to freeze affected systems during concurrent I2C operations. jz4780_i2c_set_speed() calls clk_get_rate() while the adapter lock is held, reversing the order used when CCF holds prepare_lock and enters i2c_transfer(). Reachability requires a jz4780 I2C controller, an I2C-controlled clock generator being registered or modified, and a parallel transfer on the same bus.
Summary
What happened
Deadlock in the Linux kernel jz4780 I2C driver from 4.1 allows attackers to freeze affected systems during concurrent I2C operations. jz4780_i2c_set_speed() calls clk_get_rate() while the adapter lock is held, reversing the order used when CCF holds prepare_lock and enters i2c_transfer(). Reachability requires a jz4780 I2C controller, an I2C-controlled clock generator being registered or modified, and a parallel transfer on the same bus.
The record
- CVE
- CVE-2026-74463
- Published
- Aug 15, 2026
- Updated
- Aug 15, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499
- Attack vector
- Unavailable
- Privileges
- Unavailable
Timeline
How it unfolded
- Aug 15, 2026CVE publishedPublication date reported by the CVE source.
- Aug 15, 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?
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- Affected versionversion=4.1
- Affected versionversion=ba92222ed63a12d09120df9b92f56cc990abac19 <14429dc1c756c35e106f01ff09cadccb82f5531d
- Affected versionversion=ba92222ed63a12d09120df9b92f56cc990abac19 <19b783335d62e7a2367436a6e1f1b37da1878360
- Affected versionversion=ba92222ed63a12d09120df9b92f56cc990abac19 <aa1944b52d6492c48bdd17046578aa0d953546e6
- Affected versionversion=ba92222ed63a12d09120df9b92f56cc990abac19 <b6cb47e186abba85a3b08aa3023067ab82577286
- Affected versionversion=ba92222ed63a12d09120df9b92f56cc990abac19 <d99607c888f26e8a4e9fe9772860cef4aff86bb4
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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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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