rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	3-....: (10502 ticks this GP) idle=1ffc/1/0x4000000000000000 softirq=55886/55887 fqs=4891
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:     5256          0            0
rcu: 	cputime:      190          0        52308   ==> 52510(ms)
rcu: 	(t=10502 jiffies g=44209 q=5838 ncpus=4)
CPU: 3 UID: 0 PID: 1418 Comm: aoe_tx0 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:write_comp_data+0x40/0x90 kernel/kcov.c:246
Code: 04 12 a9 00 01 ff 00 74 1b f6 c4 01 74 07 a9 00 00 ff 00 74 05 e9 c0 13 8a 09 8b 87 54 16 00 00 85 c0 74 f1 8b 87 30 16 00 00 <83> f8 03 75 e6 48 8b 87 38 16 00 00 8b bf 34 16 00 00 48 8b 30 48
RSP: 0018:ffffc90006aef9e0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffffffff86b82e8b
RDX: 0000000000000020 RSI: 0000000000000000 RDI: ffff88802bcdc900
RBP: ffff88803a8e3180 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000020 R11: 0000000000000000 R12: 0000000000000020
R13: ffff888035ce2dc0 R14: 0000000000000000 R15: ffff888035ce2000
FS:  0000000000000000(0000) GS:ffff8880d6647000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1d215d0e9c CR3: 000000000e598000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000000c DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 handle_tx+0x37b/0x620 drivers/net/caif/caif_serial.c:236
 __netdev_start_xmit include/linux/netdevice.h:5275 [inline]
 netdev_start_xmit include/linux/netdevice.h:5284 [inline]
 xmit_one net/core/dev.c:3871 [inline]
 dev_hard_start_xmit+0x121/0x7d0 net/core/dev.c:3887
 __dev_queue_xmit+0x32c1/0x4800 net/core/dev.c:4840
 dev_queue_xmit include/linux/netdevice.h:3384 [inline]
 tx+0xc4/0x130 drivers/block/aoe/aoenet.c:62
 kthread+0x1d8/0x3c0 drivers/block/aoe/aoecmd.c:1241
 kthread+0x370/0x450 kernel/kthread.c:467
 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>