CVE-2023-52516: In the Linux kernel, the following vulnerability has been resolved:  dma-debug: don't call __dma_entry_alloc_check_leak() under free_entries_lock  __dma_entry_alloc_check_leak() calls into printk -> serial console output (qcom geni) and grabs port->lock under free_entries_lock spin lock, which is a reverse locking dependency chain as qcom_geni IRQ handler can call into dma-debug code and grab free_entries_lock under port->lock.  Move __dma_entry_alloc_check_leak() call out of free_entries_lock scope so that we don't acquire serial console's port->lock under it.  Trimmed-down lockdep splat:   The existing dependency chain (in reverse order) is:                 -> #2 (free_entries_lock){-.-.}-{2:2}:         _raw_spin_lock_irqsave+0x60/0x80         dma_entry_alloc+0x38/0x110         debug_dma_map_page+0x60/0xf8         dma_map_page_attrs+0x1e0/0x230         dma_map_single_attrs.constprop.0+0x6c/0xc8         geni_se_rx_dma_prep+0x40/0xcc         qcom_geni_serial_isr+0x310/0x510         __handle_irq_event_percpu+0x110/0x244         handle_irq_event_percpu+0x20/0x54         handle_irq_event+0x50/0x88         handle_fasteoi_irq+0xa4/0xcc         handle_irq_desc+0x28/0x40         generic_handle_domain_irq+0x24/0x30         gic_handle_irq+0xc4/0x148         do_interrupt_handler+0xa4/0xb0         el1_interrupt+0x34/0x64         el1h_64_irq_handler+0x18/0x24         el1h_64_irq+0x64/0x68         arch_local_irq_enable+0x4/0x8         ____do_softirq+0x18/0x24         ...                 -> #1 (&port_lock_key){-.-.}-{2:2}:         _raw_spin_lock_irqsave+0x60/0x80         qcom_geni_serial_console_write+0x184/0x1dc         console_flush_all+0x344/0x454         console_unlock+0x94/0xf0         vprintk_emit+0x238/0x24c         vprintk_default+0x3c/0x48         vprintk+0xb4/0xbc         _printk+0x68/0x90         register_console+0x230/0x38c         uart_add_one_port+0x338/0x494         qcom_geni_serial_probe+0x390/0x424         platform_probe+0x70/0xc0         really_probe+0x148/0x280         __driver_probe_device+0xfc/0x114         driver_probe_device+0x44/0x100         __device_attach_driver+0x64/0xdc         bus_for_each_drv+0xb0/0xd8         __device_attach+0xe4/0x140         device_initial_probe+0x1c/0x28         bus_probe_device+0x44/0xb0         device_add+0x538/0x668         of_device_add+0x44/0x50         of_platform_device_create_pdata+0x94/0xc8         of_platform_bus_create+0x270/0x304         of_platform_populate+0xac/0xc4         devm_of_platform_populate+0x60/0xac         geni_se_probe+0x154/0x160         platform_probe+0x70/0xc0         ...                 -> #0 (console_owner){-...}-{0:0}:         __lock_acquire+0xdf8/0x109c         lock_acquire+0x234/0x284         console_flush_all+0x330/0x454         console_unlock+0x94/0xf0         vprintk_emit+0x238/0x24c         vprintk_default+0x3c/0x48         vprintk+0xb4/0xbc         _printk+0x68/0x90         dma_entry_alloc+0xb4/0x110         debug_dma_map_sg+0xdc/0x2f8         __dma_map_sg_attrs+0xac/0xe4         dma_map_sgtable+0x30/0x4c         get_pages+0x1d4/0x1e4 [msm]         msm_gem_pin_pages_locked+0x38/0xac [msm]         msm_gem_pin_vma_locked+0x58/0x88 [msm]         msm_ioctl_gem_submit+0xde4/0x13ac [msm]         drm_ioctl_kernel+0xe0/0x15c         drm_ioctl+0x2e8/0x3f4         vfs_ioctl+0x30/0x50         ...   Chain exists of:    console_owner --> &port_lock_key --> free_entries_lock    Possible unsafe locking scenario:          CPU0                    CPU1         ----                    ----    lock(free_entries_lock);                                 lock(&port_lock_key);                                 lock(free_entries_lock);    lock(console_owner);                  *** DEADLOCK ***   Call trace:   dump_backtrace+0xb4/0xf0   show_stack+0x20/0x30   dump_stack_lvl+0x60/0x84   dump_stack+0x18/0x24   print_circular_bug+0x1cc/0x234   check_noncircular+0x78/0xac   __lock_acquire+0xdf8/0x109c   lock_acquire+0x234/0x284   console_flush_all+0x330/0x454   consol ---truncated---