CVE-2025-38388

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> firmware: arm_ffa: Replace mutex with rwlock to avoid sleep in atomic context<br /> <br /> The current use of a mutex to protect the notifier hashtable accesses<br /> can lead to issues in the atomic context. It results in the below<br /> kernel warnings:<br /> <br /> | BUG: sleeping function called from invalid context at kernel/locking/mutex.c:258<br /> | in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 9, name: kworker/0:0<br /> | preempt_count: 1, expected: 0<br /> | RCU nest depth: 0, expected: 0<br /> | CPU: 0 UID: 0 PID: 9 Comm: kworker/0:0 Not tainted 6.14.0 #4<br /> | Workqueue: ffa_pcpu_irq_notification notif_pcpu_irq_work_fn<br /> | Call trace:<br /> | show_stack+0x18/0x24 (C)<br /> | dump_stack_lvl+0x78/0x90<br /> | dump_stack+0x18/0x24<br /> | __might_resched+0x114/0x170<br /> | __might_sleep+0x48/0x98<br /> | mutex_lock+0x24/0x80<br /> | handle_notif_callbacks+0x54/0xe0<br /> | notif_get_and_handle+0x40/0x88<br /> | generic_exec_single+0x80/0xc0<br /> | smp_call_function_single+0xfc/0x1a0<br /> | notif_pcpu_irq_work_fn+0x2c/0x38<br /> | process_one_work+0x14c/0x2b4<br /> | worker_thread+0x2e4/0x3e0<br /> | kthread+0x13c/0x210<br /> | ret_from_fork+0x10/0x20<br /> <br /> To address this, replace the mutex with an rwlock to protect the notifier<br /> hashtable accesses. This ensures that read-side locking does not sleep and<br /> multiple readers can acquire the lock concurrently, avoiding unnecessary<br /> contention and potential deadlocks. Writer access remains exclusive,<br /> preserving correctness.<br /> <br /> This change resolves warnings from lockdep about potential sleep in<br /> atomic context.