=============================
WARNING: suspicious RCU usage
5.1.0-rc3+ #8 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
3 locks held by sshd/4581:
 #0: 0000000039c30375 (sk_lock-AF_INET){+.+.}, at: lock_sock include/net/sock.h:1513 [inline]
 #0: 0000000039c30375 (sk_lock-AF_INET){+.+.}, at: tcp_sendmsg+0x1d/0x40 net/ipv4/tcp.c:1444
 #1: 0000000075760d17 (rcu_read_lock){....}, at: sock_net include/net/sock.h:2442 [inline]
 #1: 0000000075760d17 (rcu_read_lock){....}, at: __ip_queue_xmit+0x40/0x1c00 net/ipv4/ip_output.c:430
 #2: 00000000553600e1 ((&toneport->timer)){+.-.}, at: lockdep_copy_map include/linux/lockdep.h:170 [inline]
 #2: 00000000553600e1 ((&toneport->timer)){+.-.}, at: call_timer_fn+0xc9/0x5e0 kernel/time/timer.c:1315

stack backtrace:
CPU: 0 PID: 4581 Comm: sshd Not tainted 5.1.0-rc3+ #8
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+0xca/0x13e 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+0x1ac/0x270 kernel/sched/core.c:6155
 __mutex_lock_common kernel/locking/mutex.c:908 [inline]
 __mutex_lock+0xc8/0x12b0 kernel/locking/mutex.c:1072
 line6_pcm_acquire+0x30/0x210 sound/usb/line6/pcm.c:311
 call_timer_fn+0x15c/0x5e0 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+0x586/0x1400 kernel/time/timer.c:1694
 __do_softirq+0x21f/0x8bc kernel/softirq.c:293
 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1027
 </IRQ>
 do_softirq.part.0+0x3d/0x40 kernel/softirq.c:338
 do_softirq kernel/softirq.c:330 [inline]
 __local_bh_enable_ip+0x172/0x1a0 kernel/softirq.c:190
 local_bh_enable include/linux/bottom_half.h:32 [inline]
 rcu_read_unlock_bh include/linux/rcupdate.h:684 [inline]
 ip_finish_output2+0x8e7/0x1580 net/ipv4/ip_output.c:231
 ip_finish_output net/ipv4/ip_output.c:317 [inline]
 ip_finish_output+0x5ff/0xbc0 net/ipv4/ip_output.c:292
 NF_HOOK_COND include/linux/netfilter.h:278 [inline]
 ip_output+0x1f5/0x610 net/ipv4/ip_output.c:405
 dst_output include/net/dst.h:444 [inline]
 ip_local_out+0xb4/0x1a0 net/ipv4/ip_output.c:124
 __ip_queue_xmit+0x85c/0x1c00 net/ipv4/ip_output.c:505
 __tcp_transmit_skb+0x18d1/0x33a0 net/ipv4/tcp_output.c:1159
 tcp_transmit_skb net/ipv4/tcp_output.c:1175 [inline]
 tcp_write_xmit+0xe66/0x5280 net/ipv4/tcp_output.c:2400
 __tcp_push_pending_frames+0xaa/0x330 net/ipv4/tcp_output.c:2576
 tcp_push+0x4b2/0x6b0 net/ipv4/tcp.c:735
 tcp_sendmsg_locked+0x2844/0x3160 net/ipv4/tcp.c:1407
 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1445
 inet_sendmsg+0x134/0x590 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:661
 sock_write_iter+0x235/0x360 net/socket.c:988
 call_write_iter include/linux/fs.h:1863 [inline]
 new_sync_write+0x414/0x630 fs/read_write.c:474
 __vfs_write+0xcf/0x100 fs/read_write.c:487
 vfs_write+0x206/0x560 fs/read_write.c:549
 ksys_write+0xcc/0x1d0 fs/read_write.c:598
 do_syscall_64+0xbd/0x500 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fe4b44f2370
Code: 73 01 c3 48 8b 0d c8 4a 2b 00 31 d2 48 29 c2 64 89 11 48 83 c8 ff eb ea 90 90 83 3d 85 a2 2b 00 00 75 10 b8 01 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 0e 8a 01 00 48 89 04 24
RSP: 002b:00007ffeffb76b38 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000004028 RCX: 00007fe4b44f2370
RDX: 0000000000004028 RSI: 00005582beff21a0 RDI: 0000000000000003
RBP: 00005582beff21a0 R08: 0000000000000001 R09: 286f695f6c6f7274
R10: 6666666666667830 R11: 0000000000000246 R12: 00007ffeffb76b9c
R13: 00005582be771fb4 R14: 0000000000000028 R15: 00005582be773ca0
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:908
in_atomic(): 1, irqs_disabled(): 0, pid: 4581, name: sshd
3 locks held by sshd/4581:
 #0: 0000000039c30375 (sk_lock-AF_INET){+.+.}, at: lock_sock include/net/sock.h:1513 [inline]
 #0: 0000000039c30375 (sk_lock-AF_INET){+.+.}, at: tcp_sendmsg+0x1d/0x40 net/ipv4/tcp.c:1444
 #1: 0000000075760d17 (rcu_read_lock){....}, at: sock_net include/net/sock.h:2442 [inline]
 #1: 0000000075760d17 (rcu_read_lock){....}, at: __ip_queue_xmit+0x40/0x1c00 net/ipv4/ip_output.c:430
 #2: 00000000553600e1 ((&toneport->timer)){+.-.}, at: lockdep_copy_map include/linux/lockdep.h:170 [inline]
 #2: 00000000553600e1 ((&toneport->timer)){+.-.}, at: call_timer_fn+0xc9/0x5e0 kernel/time/timer.c:1315
CPU: 0 PID: 4581 Comm: sshd Not tainted 5.1.0-rc3+ #8
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+0xca/0x13e lib/dump_stack.c:113
 ___might_sleep.cold+0x10f/0x129 kernel/sched/core.c:6190
 __mutex_lock_common kernel/locking/mutex.c:908 [inline]
 __mutex_lock+0xc8/0x12b0 kernel/locking/mutex.c:1072
 line6_pcm_acquire+0x30/0x210 sound/usb/line6/pcm.c:311
 call_timer_fn+0x15c/0x5e0 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+0x586/0x1400 kernel/time/timer.c:1694
 __do_softirq+0x21f/0x8bc kernel/softirq.c:293
 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1027
 </IRQ>
 do_softirq.part.0+0x3d/0x40 kernel/softirq.c:338
 do_softirq kernel/softirq.c:330 [inline]
 __local_bh_enable_ip+0x172/0x1a0 kernel/softirq.c:190
 local_bh_enable include/linux/bottom_half.h:32 [inline]
 rcu_read_unlock_bh include/linux/rcupdate.h:684 [inline]
 ip_finish_output2+0x8e7/0x1580 net/ipv4/ip_output.c:231
 ip_finish_output net/ipv4/ip_output.c:317 [inline]
 ip_finish_output+0x5ff/0xbc0 net/ipv4/ip_output.c:292
 NF_HOOK_COND include/linux/netfilter.h:278 [inline]
 ip_output+0x1f5/0x610 net/ipv4/ip_output.c:405
 dst_output include/net/dst.h:444 [inline]
 ip_local_out+0xb4/0x1a0 net/ipv4/ip_output.c:124
 __ip_queue_xmit+0x85c/0x1c00 net/ipv4/ip_output.c:505
 __tcp_transmit_skb+0x18d1/0x33a0 net/ipv4/tcp_output.c:1159
 tcp_transmit_skb net/ipv4/tcp_output.c:1175 [inline]
 tcp_write_xmit+0xe66/0x5280 net/ipv4/tcp_output.c:2400
 __tcp_push_pending_frames+0xaa/0x330 net/ipv4/tcp_output.c:2576
 tcp_push+0x4b2/0x6b0 net/ipv4/tcp.c:735
 tcp_sendmsg_locked+0x2844/0x3160 net/ipv4/tcp.c:1407
 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1445
 inet_sendmsg+0x134/0x590 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:661
 sock_write_iter+0x235/0x360 net/socket.c:988
 call_write_iter include/linux/fs.h:1863 [inline]
 new_sync_write+0x414/0x630 fs/read_write.c:474
 __vfs_write+0xcf/0x100 fs/read_write.c:487
 vfs_write+0x206/0x560 fs/read_write.c:549
 ksys_write+0xcc/0x1d0 fs/read_write.c:598
 do_syscall_64+0xbd/0x500 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fe4b44f2370
Code: 73 01 c3 48 8b 0d c8 4a 2b 00 31 d2 48 29 c2 64 89 11 48 83 c8 ff eb ea 90 90 83 3d 85 a2 2b 00 00 75 10 b8 01 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 0e 8a 01 00 48 89 04 24
RSP: 002b:00007ffeffb76b38 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000004028 RCX: 00007fe4b44f2370
RDX: 0000000000004028 RSI: 00005582beff21a0 RDI: 0000000000000003
RBP: 00005582beff21a0 R08: 0000000000000001 R09: 286f695f6c6f7274
R10: 6666666666667830 R11: 0000000000000246 R12: 00007ffeffb76b9c
R13: 00005582be771fb4 R14: 0000000000000028 R15: 00005582be773ca0
==================================================================
BUG: KASAN: null-ptr-deref in memset include/linux/string.h:337 [inline]
BUG: KASAN: null-ptr-deref in submit_audio_out_urb+0x919/0x1780 sound/usb/line6/playback.c:246
Write of size 20 at addr 0000000000000010 by task sshd/4581

CPU: 0 PID: 4581 Comm: sshd Tainted: G        W         5.1.0-rc3+ #8
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+0xca/0x13e lib/dump_stack.c:113
 kasan_report.cold+0x5/0x35 mm/kasan/report.c:321
 memset+0x20/0x40 mm/kasan/common.c:115
 memset include/linux/string.h:337 [inline]
 submit_audio_out_urb+0x919/0x1780 sound/usb/line6/playback.c:246
 line6_submit_audio_out_all_urbs+0xc9/0x120 sound/usb/line6/playback.c:295
 line6_stream_start+0x156/0x1f0 sound/usb/line6/pcm.c:199
 line6_pcm_acquire+0x134/0x210 sound/usb/line6/pcm.c:322
 call_timer_fn+0x15c/0x5e0 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+0x586/0x1400 kernel/time/timer.c:1694
 __do_softirq+0x21f/0x8bc kernel/softirq.c:293
 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1027
 </IRQ>
 do_softirq.part.0+0x3d/0x40 kernel/softirq.c:338
 do_softirq kernel/softirq.c:330 [inline]
 __local_bh_enable_ip+0x172/0x1a0 kernel/softirq.c:190
 local_bh_enable include/linux/bottom_half.h:32 [inline]
 rcu_read_unlock_bh include/linux/rcupdate.h:684 [inline]
 ip_finish_output2+0x8e7/0x1580 net/ipv4/ip_output.c:231
 ip_finish_output net/ipv4/ip_output.c:317 [inline]
 ip_finish_output+0x5ff/0xbc0 net/ipv4/ip_output.c:292
 NF_HOOK_COND include/linux/netfilter.h:278 [inline]
 ip_output+0x1f5/0x610 net/ipv4/ip_output.c:405
 dst_output include/net/dst.h:444 [inline]
 ip_local_out+0xb4/0x1a0 net/ipv4/ip_output.c:124
 __ip_queue_xmit+0x85c/0x1c00 net/ipv4/ip_output.c:505
 __tcp_transmit_skb+0x18d1/0x33a0 net/ipv4/tcp_output.c:1159
 tcp_transmit_skb net/ipv4/tcp_output.c:1175 [inline]
 tcp_write_xmit+0xe66/0x5280 net/ipv4/tcp_output.c:2400
 __tcp_push_pending_frames+0xaa/0x330 net/ipv4/tcp_output.c:2576
 tcp_push+0x4b2/0x6b0 net/ipv4/tcp.c:735
 tcp_sendmsg_locked+0x2844/0x3160 net/ipv4/tcp.c:1407
 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1445
 inet_sendmsg+0x134/0x590 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:661
 sock_write_iter+0x235/0x360 net/socket.c:988
 call_write_iter include/linux/fs.h:1863 [inline]
 new_sync_write+0x414/0x630 fs/read_write.c:474
 __vfs_write+0xcf/0x100 fs/read_write.c:487
 vfs_write+0x206/0x560 fs/read_write.c:549
 ksys_write+0xcc/0x1d0 fs/read_write.c:598
 do_syscall_64+0xbd/0x500 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fe4b44f2370
Code: 73 01 c3 48 8b 0d c8 4a 2b 00 31 d2 48 29 c2 64 89 11 48 83 c8 ff eb ea 90 90 83 3d 85 a2 2b 00 00 75 10 b8 01 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 0e 8a 01 00 48 89 04 24
RSP: 002b:00007ffeffb76b38 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000004028 RCX: 00007fe4b44f2370
RDX: 0000000000004028 RSI: 00005582beff21a0 RDI: 0000000000000003
RBP: 00005582beff21a0 R08: 0000000000000001 R09: 286f695f6c6f7274
R10: 6666666666667830 R11: 0000000000000246 R12: 00007ffeffb76b9c
R13: 00005582be771fb4 R14: 0000000000000028 R15: 00005582be773ca0
==================================================================