Description
In the Linux kernel, the following vulnerability has been resolved: firmware: arm_ffa: Replace mutex with rwlock to avoid sleep in atomic context The current use of a mutex to protect the notifier hashtable accesses can lead to issues in the atomic context. It results in the below kernel warnings: | BUG: sleeping function called from invalid context at kernel/locking/mutex.c:258 | in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 9, name: kworker/0:0 | preempt_count: 1, expected: 0 | RCU nest depth: 0, expected: 0 | CPU: 0 UID: 0 PID: 9 Comm: kworker/0:0 Not tainted 6.14.0 #4 | Workqueue: ffa_pcpu_irq_notification notif_pcpu_irq_work_fn | Call trace: | show_stack+0x18/0x24 (C) | dump_stack_lvl+0x78/0x90 | dump_stack+0x18/0x24 | __might_resched+0x114/0x170 | __might_sleep+0x48/0x98 | mutex_lock+0x24/0x80 | handle_notif_callbacks+0x54/0xe0 | notif_get_and_handle+0x40/0x88 | generic_exec_single+0x80/0xc0 | smp_call_function_single+0xfc/0x1a0 | notif_pcpu_irq_work_fn+0x2c/0x38 | process_one_work+0x14c/0x2b4 | worker_thread+0x2e4/0x3e0 | kthread+0x13c/0x210 | ret_from_fork+0x10/0x20 To address this, replace the mutex with an rwlock to protect the notifier hashtable accesses. This ensures that read-side locking does not sleep and multiple readers can acquire the lock concurrently, avoiding unnecessary contention and potential deadlocks. Writer access remains exclusive, preserving correctness. This change resolves warnings from lockdep about potential sleep in atomic context.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
e0573444edbf4ee7e3c191d3d08a4ccbd26628be to < 31405510a48dcf054abfa5b7b8d70ce1b27d1f13affectede0573444edbf4ee7e3c191d3d08a4ccbd26628be to < 8986f8f61b482c0e6efd28f0b2423d9640c20eb1affectede0573444edbf4ee7e3c191d3d08a4ccbd26628be to < 9ca7a421229bbdfbe2e1e628cff5cfa782720a10affected
Linux Linux
Default version status: affected
6.7affected0 to < 6.7unaffected6.12.37 to ≤ 6.12.*unaffected6.15.6 to ≤ 6.15.*unaffected6.16 to ≤ *unaffected