CVE-2021-47271

In the Linux kernel, the following vulnerability has been resolved: usb:
cdnsp: Fix deadlock issue in cdnsp_thread_irq_handler Patch fixes the
following critical issue caused by deadlock which has been detected during
testing NCM class: smp: csd: Detected non-responsive CSD lock (#1) on CPU#0
smp: csd: CSD lock (#1) unresponsive. … RIP:
0010:native_queued_spin_lock_slowpath+0x61/0x1d0 RSP: 0018:ffffbc494011cde0
EFLAGS: 00000002 RAX: 0000000000000101 RBX: ffff9ee8116b4a68 RCX:
0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI:
ffff9ee8116b4658 RBP: ffffbc494011cde0 R08: 0000000000000001 R09:
0000000000000000 R10: ffff9ee8116b4670 R11: 0000000000000000 R12:
ffff9ee8116b4658 R13: ffff9ee8116b4670 R14: 0000000000000246 R15:
ffff9ee8116b4658 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2:
00007f7bcc41a830 CR3: 000000007a612003 CR4: 00000000001706e0 Call Trace:
<IRQ> do_raw_spin_lock+0xc0/0xd0 _raw_spin_lock_irqsave+0x95/0xa0
cdnsp_gadget_ep_queue.cold+0x88/0x107 [cdnsp_udc_pci]
usb_ep_queue+0x35/0x110 eth_start_xmit+0x220/0x3d0 [u_ether]
ncm_tx_timeout+0x34/0x40 [usb_f_ncm] ? ncm_free_inst+0x50/0x50 [usb_f_ncm]
__hrtimer_run_queues+0xac/0x440 hrtimer_run_softirq+0x8c/0xb0
__do_softirq+0xcf/0x428 asm_call_irq_on_stack+0x12/0x20 </IRQ>
do_softirq_own_stack+0x61/0x70 irq_exit_rcu+0xc1/0xd0
sysvec_apic_timer_interrupt+0x52/0xb0
asm_sysvec_apic_timer_interrupt+0x12/0x20 RIP:
0010:do_raw_spin_trylock+0x18/0x40 RSP: 0018:ffffbc494138bda8 EFLAGS:
00000246 RAX: 0000000000000000 RBX: ffff9ee8116b4658 RCX: 0000000000000000
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff9ee8116b4658 RBP:
ffffbc494138bda8 R08: 0000000000000001 R09: 0000000000000000 R10:
ffff9ee8116b4670 R11: 0000000000000000 R12: ffff9ee8116b4658 R13:
ffff9ee8116b4670 R14: ffff9ee7b5c73d80 R15: ffff9ee8116b4000
_raw_spin_lock+0x3d/0x70 ? cdnsp_thread_irq_handler.cold+0x32/0x112c
[cdnsp_udc_pci] cdnsp_thread_irq_handler.cold+0x32/0x112c [cdnsp_udc_pci] ?
cdnsp_remove_request+0x1f0/0x1f0 [cdnsp_udc_pci] ?
cdnsp_thread_irq_handler+0x5/0xa0 [cdnsp_udc_pci] ? irq_thread+0xa0/0x1c0
irq_thread_fn+0x28/0x60 irq_thread+0x105/0x1c0 ? __kthread_parkme+0x42/0x90
? irq_forced_thread_fn+0x90/0x90 ? wake_threads_waitq+0x30/0x30 ?
irq_thread_check_affinity+0xe0/0xe0 kthread+0x12a/0x160 ?
kthread_park+0x90/0x90 ret_from_fork+0x22/0x30 The root cause of issue is
spin_lock/spin_unlock instruction instead
spin_lock_irqsave/spin_lock_irqrestore in cdnsp_thread_irq_handler
function.