=============================
WARNING: suspicious RCU usage
5.1.0-rc3-319004-g43151d6 #6 Not tainted
-----------------------------
include/linux/rcupdate.h:267 Illegal context switch in RCU read-side critical section!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
5 locks held by net.agent/6487:
 #0: 000000006e33a6bb (&mm->mmap_sem){++++}, at: do_user_addr_fault arch/x86/mm/fault.c:1416 [inline]
 #0: 000000006e33a6bb (&mm->mmap_sem){++++}, at: __do_page_fault+0x33d/0xd20 arch/x86/mm/fault.c:1541
 #1: 00000000c769cb0a (rcu_read_lock){....}, at: filemap_map_pages+0xf3/0x10b0 mm/filemap.c:2690
 #2: 00000000ce8b6d53 (&(ptlock_ptr(page))->rlock#2){+.+.}, at: spin_lock include/linux/spinlock.h:329 [inline]
 #2: 00000000ce8b6d53 (&(ptlock_ptr(page))->rlock#2){+.+.}, at: pte_alloc_one_map mm/memory.c:3116 [inline]
 #2: 00000000ce8b6d53 (&(ptlock_ptr(page))->rlock#2){+.+.}, at: alloc_set_pte+0xd9d/0x17a0 mm/memory.c:3247
 #3: 00000000c769cb0a (rcu_read_lock){....}, at: lock_page_memcg+0x5/0x240 mm/memcontrol.c:1882
 #4: 0000000078ac449c ((&toneport->timer)){+.-.}, at: lockdep_copy_map include/linux/lockdep.h:170 [inline]
 #4: 0000000078ac449c ((&toneport->timer)){+.-.}, at: call_timer_fn+0xce/0x5f0 kernel/time/timer.c:1315

stack backtrace:
CPU: 1 PID: 6487 Comm: net.agent Not tainted 5.1.0-rc3-319004-g43151d6 #6
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0xe8/0x16e lib/dump_stack.c:113
 rcu_preempt_sleep_check include/linux/rcupdate.h:267 [inline]
 rcu_preempt_sleep_check include/linux/rcupdate.h:265 [inline]
 ___might_sleep+0x1b6/0x280 kernel/sched/core.c:6155
 __mutex_lock_common kernel/locking/mutex.c:908 [inline]
 __mutex_lock+0xcd/0x12b0 kernel/locking/mutex.c:1072
 line6_pcm_acquire+0x35/0x210 sound/usb/line6/pcm.c:311
 call_timer_fn+0x161/0x5f0 kernel/time/timer.c:1325
 expire_timers kernel/time/timer.c:1362 [inline]
 __run_timers kernel/time/timer.c:1681 [inline]
 __run_timers kernel/time/timer.c:1649 [inline]
 run_timer_softirq+0x58b/0x1400 kernel/time/timer.c:1694
 __do_softirq+0x22a/0x8cd kernel/softirq.c:293
 invoke_softirq kernel/softirq.c:374 [inline]
 irq_exit+0x187/0x1b0 kernel/softirq.c:414
 exiting_irq arch/x86/include/asm/apic.h:536 [inline]
 smp_apic_timer_interrupt+0xfe/0x4a0 arch/x86/kernel/apic/apic.c:1062
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
 </IRQ>
RIP: 0010:lock_release+0x16/0x770 kernel/locking/lockdep.c:4220
Code: cb 93 e8 3d e7 50 00 e9 ff fd ff ff 0f 1f 84 00 00 00 00 00 48 b8 00 00 00 00 00 fc ff df 41 57 41 56 41 55 41 54 49 89 d4 55 <48> 89 fd 53 48 83 c4 80 48 c7 44 24 20 b3 8a b5 41 48 8d 5c 24 20
RSP: 0000:ffff888074a87b60 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: dffffc0000000000 RBX: ffff888074a87da8 RCX: ffffffff815f0a0c
RDX: ffffffff81add924 RSI: 0000000000000001 RDI: ffffffff917d62e0
RBP: ffffea0002b41d00 R08: ffff888093493100 R09: ffffed1015a25c28
R10: ffffed1015a25c27 R11: ffff8880ad12e13b R12: ffffffff81add924
R13: 0000000000000000 R14: ffff888074471988 R15: ffff888097223a80
 alloc_set_pte+0xf17/0x17a0 mm/memory.c:3268
 filemap_map_pages+0xe4a/0x10b0 mm/filemap.c:2743
 do_fault_around mm/memory.c:3411 [inline]
 do_read_fault mm/memory.c:3445 [inline]
 do_fault mm/memory.c:3579 [inline]
 handle_pte_fault mm/memory.c:3810 [inline]
 __handle_mm_fault+0x2d97/0x3870 mm/memory.c:3934
 handle_mm_fault+0x373/0x9e0 mm/memory.c:3971
 do_user_addr_fault arch/x86/mm/fault.c:1475 [inline]
 __do_page_fault+0x606/0xd20 arch/x86/mm/fault.c:1541
 page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1143
RIP: 0033:0x40a2a6
Code: Bad RIP value.
RSP: 002b:00007fff6b81a930 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 000000000061dcd0 RCX: 0000000000000001
RDX: 00007fc11ed3fe40 RSI: 0000000000000000 RDI: 00007fc11ed3e6c0
RBP: 000000000061e330 R08: 0000000000001954 R09: 0000000000001954
R10: 00007fc11ef5b9d0 R11: 0000000000000246 R12: 000000000061e240
R13: 0000000000000000 R14: 0000000000000002 R15: 000000000061e330
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:908
in_atomic(): 1, irqs_disabled(): 0, pid: 6487, name: net.agent
5 locks held by net.agent/6487:
 #0: 000000006e33a6bb (&mm->mmap_sem){++++}, at: do_user_addr_fault arch/x86/mm/fault.c:1416 [inline]
 #0: 000000006e33a6bb (&mm->mmap_sem){++++}, at: __do_page_fault+0x33d/0xd20 arch/x86/mm/fault.c:1541
 #1: 00000000c769cb0a (rcu_read_lock){....}, at: filemap_map_pages+0xf3/0x10b0 mm/filemap.c:2690
 #2: 00000000ce8b6d53 (&(ptlock_ptr(page))->rlock#2){+.+.}, at: spin_lock include/linux/spinlock.h:329 [inline]
 #2: 00000000ce8b6d53 (&(ptlock_ptr(page))->rlock#2){+.+.}, at: pte_alloc_one_map mm/memory.c:3116 [inline]
 #2: 00000000ce8b6d53 (&(ptlock_ptr(page))->rlock#2){+.+.}, at: alloc_set_pte+0xd9d/0x17a0 mm/memory.c:3247
 #3: 00000000c769cb0a (rcu_read_lock){....}, at: lock_page_memcg+0x5/0x240 mm/memcontrol.c:1882
 #4: 0000000078ac449c ((&toneport->timer)){+.-.}, at: lockdep_copy_map include/linux/lockdep.h:170 [inline]
 #4: 0000000078ac449c ((&toneport->timer)){+.-.}, at: call_timer_fn+0xce/0x5f0 kernel/time/timer.c:1315
CPU: 1 PID: 6487 Comm: net.agent Not tainted 5.1.0-rc3-319004-g43151d6 #6
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0xe8/0x16e lib/dump_stack.c:113
 ___might_sleep.cold+0x11c/0x136 kernel/sched/core.c:6190
 __mutex_lock_common kernel/locking/mutex.c:908 [inline]
 __mutex_lock+0xcd/0x12b0 kernel/locking/mutex.c:1072
 line6_pcm_acquire+0x35/0x210 sound/usb/line6/pcm.c:311
 call_timer_fn+0x161/0x5f0 kernel/time/timer.c:1325
 expire_timers kernel/time/timer.c:1362 [inline]
 __run_timers kernel/time/timer.c:1681 [inline]
 __run_timers kernel/time/timer.c:1649 [inline]
 run_timer_softirq+0x58b/0x1400 kernel/time/timer.c:1694
 __do_softirq+0x22a/0x8cd kernel/softirq.c:293
 invoke_softirq kernel/softirq.c:374 [inline]
 irq_exit+0x187/0x1b0 kernel/softirq.c:414
 exiting_irq arch/x86/include/asm/apic.h:536 [inline]
 smp_apic_timer_interrupt+0xfe/0x4a0 arch/x86/kernel/apic/apic.c:1062
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
 </IRQ>
RIP: 0010:lock_release+0x16/0x770 kernel/locking/lockdep.c:4220
Code: cb 93 e8 3d e7 50 00 e9 ff fd ff ff 0f 1f 84 00 00 00 00 00 48 b8 00 00 00 00 00 fc ff df 41 57 41 56 41 55 41 54 49 89 d4 55 <48> 89 fd 53 48 83 c4 80 48 c7 44 24 20 b3 8a b5 41 48 8d 5c 24 20
RSP: 0000:ffff888074a87b60 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: dffffc0000000000 RBX: ffff888074a87da8 RCX: ffffffff815f0a0c
RDX: ffffffff81add924 RSI: 0000000000000001 RDI: ffffffff917d62e0
RBP: ffffea0002b41d00 R08: ffff888093493100 R09: ffffed1015a25c28
R10: ffffed1015a25c27 R11: ffff8880ad12e13b R12: ffffffff81add924
R13: 0000000000000000 R14: ffff888074471988 R15: ffff888097223a80
 alloc_set_pte+0xf17/0x17a0 mm/memory.c:3268
 filemap_map_pages+0xe4a/0x10b0 mm/filemap.c:2743
 do_fault_around mm/memory.c:3411 [inline]
 do_read_fault mm/memory.c:3445 [inline]
 do_fault mm/memory.c:3579 [inline]
 handle_pte_fault mm/memory.c:3810 [inline]
 __handle_mm_fault+0x2d97/0x3870 mm/memory.c:3934
 handle_mm_fault+0x373/0x9e0 mm/memory.c:3971
 do_user_addr_fault arch/x86/mm/fault.c:1475 [inline]
 __do_page_fault+0x606/0xd20 arch/x86/mm/fault.c:1541
 page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1143
RIP: 0033:0x40a2a6
Code: Bad RIP value.
RSP: 002b:00007fff6b81a930 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 000000000061dcd0 RCX: 0000000000000001
RDX: 00007fc11ed3fe40 RSI: 0000000000000000 RDI: 00007fc11ed3e6c0
RBP: 000000000061e330 R08: 0000000000001954 R09: 0000000000001954
R10: 00007fc11ef5b9d0 R11: 0000000000000246 R12: 000000000061e240
R13: 0000000000000000 R14: 0000000000000002 R15: 000000000061e330
==================================================================
BUG: KASAN: null-ptr-deref in memset include/linux/string.h:337 [inline]
BUG: KASAN: null-ptr-deref in submit_audio_out_urb+0x91e/0x1780 sound/usb/line6/playback.c:246
Write of size 20 at addr 0000000000000010 by task net.agent/6487

CPU: 1 PID: 6487 Comm: net.agent Tainted: G        W         5.1.0-rc3-319004-g43151d6 #6
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0xe8/0x16e lib/dump_stack.c:113
 kasan_report.cold+0x5/0x3c mm/kasan/report.c:321
 memset+0x20/0x40 mm/kasan/common.c:115
 memset include/linux/string.h:337 [inline]
 submit_audio_out_urb+0x91e/0x1780 sound/usb/line6/playback.c:246
 line6_submit_audio_out_all_urbs+0xce/0x120 sound/usb/line6/playback.c:295
 line6_stream_start+0x15b/0x1f0 sound/usb/line6/pcm.c:199
 line6_pcm_acquire+0x139/0x210 sound/usb/line6/pcm.c:322
 call_timer_fn+0x161/0x5f0 kernel/time/timer.c:1325
 expire_timers kernel/time/timer.c:1362 [inline]
 __run_timers kernel/time/timer.c:1681 [inline]
 __run_timers kernel/time/timer.c:1649 [inline]
 run_timer_softirq+0x58b/0x1400 kernel/time/timer.c:1694
 __do_softirq+0x22a/0x8cd kernel/softirq.c:293
 invoke_softirq kernel/softirq.c:374 [inline]
 irq_exit+0x187/0x1b0 kernel/softirq.c:414
 exiting_irq arch/x86/include/asm/apic.h:536 [inline]
 smp_apic_timer_interrupt+0xfe/0x4a0 arch/x86/kernel/apic/apic.c:1062
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
 </IRQ>
RIP: 0010:lock_release+0x16/0x770 kernel/locking/lockdep.c:4220
Code: cb 93 e8 3d e7 50 00 e9 ff fd ff ff 0f 1f 84 00 00 00 00 00 48 b8 00 00 00 00 00 fc ff df 41 57 41 56 41 55 41 54 49 89 d4 55 <48> 89 fd 53 48 83 c4 80 48 c7 44 24 20 b3 8a b5 41 48 8d 5c 24 20
RSP: 0000:ffff888074a87b60 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: dffffc0000000000 RBX: ffff888074a87da8 RCX: ffffffff815f0a0c
RDX: ffffffff81add924 RSI: 0000000000000001 RDI: ffffffff917d62e0
RBP: ffffea0002b41d00 R08: ffff888093493100 R09: ffffed1015a25c28
R10: ffffed1015a25c27 R11: ffff8880ad12e13b R12: ffffffff81add924
R13: 0000000000000000 R14: ffff888074471988 R15: ffff888097223a80
 alloc_set_pte+0xf17/0x17a0 mm/memory.c:3268
 filemap_map_pages+0xe4a/0x10b0 mm/filemap.c:2743
 do_fault_around mm/memory.c:3411 [inline]
 do_read_fault mm/memory.c:3445 [inline]
 do_fault mm/memory.c:3579 [inline]
 handle_pte_fault mm/memory.c:3810 [inline]
 __handle_mm_fault+0x2d97/0x3870 mm/memory.c:3934
 handle_mm_fault+0x373/0x9e0 mm/memory.c:3971
 do_user_addr_fault arch/x86/mm/fault.c:1475 [inline]
 __do_page_fault+0x606/0xd20 arch/x86/mm/fault.c:1541
 page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1143
RIP: 0033:0x40a2a6
Code: Bad RIP value.
RSP: 002b:00007fff6b81a930 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 000000000061dcd0 RCX: 0000000000000001
RDX: 00007fc11ed3fe40 RSI: 0000000000000000 RDI: 00007fc11ed3e6c0
RBP: 000000000061e330 R08: 0000000000001954 R09: 0000000000001954
R10: 00007fc11ef5b9d0 R11: 0000000000000246 R12: 000000000061e240
R13: 0000000000000000 R14: 0000000000000002 R15: 000000000061e330
==================================================================