CVE-2023-53712

A logic error was found in the Linux kernel's ARM kexec crash handling in the SMP stop notification code. A local user can trigger this issue by causing a kernel panic from a high-resolution timer interrupt context (such as a software watchdog expiration), where the crash shutdown path attempts to synchronously stop other CPUs with interrupts disabled. This violates SMP call constraints and results in warnings, potential deadlocks, or failure to properly capture crash state for kdump.

During a kernel panic, the crash handling code needs to stop all other CPUs before capturing system state for kdump. On ARM, machine_crash_shutdown() calls crash_smp_send_stop() which uses synchronous SMP function calls to notify other cores. When the panic originates from an hrtimer interrupt (like the software watchdog), interrupts are already disabled on the panicking CPU. Making synchronous cross-CPU calls in this state can deadlock if target CPUs are waiting for interrupts, and triggers kernel warnings about improper SMP call context. This is ARM-architecture specific and primarily affects systems using kdump for crash analysis. The bug doesn't enable privilege escalation but can prevent successful crash dump collection.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

This issue is specific to ARM platforms using kexec/kdump. No runtime mitigation is available.