System hang via recursive serial port locking
Published Jul 25, 2026 · Updated Jul 25, 2026
Deadlock in the Linux kernel Samsung serial driver allows attackers to hang affected systems when console flow control is enabled. The s3c24xx_serial_rx_enable() and s3c24xx_serial_rx_disable() helpers call uart_port_lock_irqsave() even though their callers already hold the nonrecursive port->lock spinlock. The condition requires UPF_CONS_FLOW and a transmit stop or start path; the resulting same-CPU lockup interrupts service rather than corrupting data or executing code.
Summary
What happened
Deadlock in the Linux kernel Samsung serial driver allows attackers to hang affected systems when console flow control is enabled. The s3c24xx_serial_rx_enable() and s3c24xx_serial_rx_disable() helpers call uart_port_lock_irqsave() even though their callers already hold the nonrecursive port->lock spinlock. The condition requires UPF_CONS_FLOW and a transmit stop or start path; the resulting same-CPU lockup interrupts service rather than corrupting data or executing code.
The record
- CVE
- CVE-2026-64528
- Published
- Jul 25, 2026
- Updated
- Jul 25, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- T1499.004
- Attack vector
- Unavailable
- Privileges
- Unavailable
Timeline
How it unfolded
- Jul 25, 2026CVE publishedPublication date reported by the CVE source.
- Jul 25, 2026Record updatedLatest update available in the CVE record.
Exploitability
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Is a vulnerable build present?
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- Affected versionversion=2.6.27
- Affected versionversion=b497549a035c2a81b71c7a27f2b00c8a16c09423 <10014eb7eee351f7b587f8ac85830f0c9343cb9a
- Affected versionversion=b497549a035c2a81b71c7a27f2b00c8a16c09423 <14143ec10d69f42806b5d7b046f0fd1b835831ae
- Affected versionversion=b497549a035c2a81b71c7a27f2b00c8a16c09423 <9c92b42207978559e32903c3098aaf5c5b5788b2
- Affected versionversion=b497549a035c2a81b71c7a27f2b00c8a16c09423 <9fd48937046efc9abb89379d63ee9cc5c661d711
- Affected versionversion=b497549a035c2a81b71c7a27f2b00c8a16c09423 <a3bb136bff5e6a5e48cdd813246c9c4686feaaa9
- Affected versionversion=b497549a035c2a81b71c7a27f2b00c8a16c09423 <a9c22e0f93ba18322a6623ecdda2f0cd858ca350
- Affected versionversion=b497549a035c2a81b71c7a27f2b00c8a16c09423 <ee9eb72be95490602c493db050c73d925c3a4d74
- Affected versionversion=b497549a035c2a81b71c7a27f2b00c8a16c09423 <f4c3e63fa8639aedf96fb200d9939945a9eed51e
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Attacks
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