Executive brief
A deadlock vulnerability was identified in the Samsung serial driver of the Linux kernel. This issue occurs when console flow control is enabled, potentially causing the system to hang or become unresponsive during serial data transmission. This affects the availability of systems using specific Samsung serial hardware interfaces.
Technical details
A deadlock exists in the Samsung serial driver (drivers/tty/serial/samsung_tty.c) due to redundant lock acquisition. When console flow control (UPF_CONS_FLOW) is enabled, the functions s3c24xx_serial_rx_enable() and s3c24xx_serial_rx_disable() attempt to acquire the port->lock spinlock using uart_port_lock_irqsave(). However, these functions are called by .stop_tx() and .start_tx() callbacks which are already executed with the port->lock held by the serial core framework. Since Linux spinlocks are non-recursive, this results in a CPU deadlock. The fix involves removing the redundant lock acquisitions in the RX helper functions.
Affected products
- Linux Linux Kernel b497549a035c to a3bb136bff5e
Timeline
- 2026-05-15: disclosed: Initial patch submission by Tudor Ambarus
- 2026-06-19: patched: Patch committed to stable tree
- 2026-07-25: advisory: CVE-2026-64528 published
References
- https://git.kernel.org/stable/c/10014eb7eee351f7b587f8ac85830f0c9343cb9a
- https://git.kernel.org/stable/c/14143ec10d69f42806b5d7b046f0fd1b835831ae
- https://git.kernel.org/stable/c/9c92b42207978559e32903c3098aaf5c5b5788b2
- https://git.kernel.org/stable/c/9fd48937046efc9abb89379d63ee9cc5c661d711
- https://git.kernel.org/stable/c/a3bb136bff5e6a5e48cdd813246c9c4686feaaa9
- https://git.kernel.org/stable/c/a9c22e0f93ba18322a6623ecdda2f0cd858ca350
- https://git.kernel.org/stable/c/ee9eb72be95490602c493db050c73d925c3a4d74