Receive Interrupt Oversight in Renesas RA SCI UART Driver

CVE-2026-90585

What is CVE-2026-90585?

The Renesas RA SCI UART driver's error handling mechanism contains a flaw that can lead to an infinite interrupt loop. When the receive-error interrupt service routine (ISR) is triggered due to line errors and no user-defined callback is registered, the ISR enters an endless cycle without clearing the relevant error flags. This occurs under specific configurations where the interrupt is incorrectly re-enabled by default settings. Consequently, a data transmission error causes the system to hang, requiring a manual reset. This issue emphasizes the need for proper error callback registration in the UART driver to ensure system stability during UART communication.

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