CVE-2024-48876

In the Linux kernel, the following vulnerability has been resolved:

stackdepot: fix stack_depot_save_flags() in NMI context

Per documentation, stack_depot_save_flags() was meant to be usable from NMI context if STACK_DEPOT_FLAG_CAN_ALLOC is unset. However, it still would try to take the pool_lock in an attempt to save a stack trace in the current pool (if space is available).

This could result in deadlock if an NMI is handled while pool_lock is already held. To avoid deadlock, only try to take the lock in NMI context and give up if unsuccessful.

The documentation is fixed to clearly convey this.

This vulnerability is classified as Moderate impact because successful exploitation is restricted to local denial of service via a kernel hang and cannot lead to code execution or privilege escalation. Under standard Red Hat Enterprise Linux deployments, triggering this condition requires an uncommon timing race where an interrupt occurs in non-maskable interrupt (NMI) context precisely while the stack depot spinlock is held, typically during kernel tracing or diagnostic events. Consequently, the flaw presents limited practical exposure in production systems.

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.