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WARNING: kernel/rcu/tree_stall.h:1049 at rcu_check_gp_start_stall.part.0+0x1c4/0x4b0 kernel/rcu/tree_stall.h:1049, CPU#0: syz.3.1694/11946
Modules linked in:
CPU: 0 UID: 0 PID: 11946 Comm: syz.3.1694 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:rcu_check_gp_start_stall.part.0+0x1c4/0x4b0 kernel/rcu/tree_stall.h:1049
Code: 88 61 01 00 00 be 04 00 00 00 48 c7 c7 40 d3 19 9b e8 80 fe 87 00 b8 01 00 00 00 87 05 d5 21 2d 19 85 c0 0f 85 3d 01 00 00 90 <0f> 0b 90 48 c7 c3 c4 fb d7 90 48 81 fd c0 06 7f 8e 74 5a 48 b8 00
RSP: 0018:ffffc90000007de8 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000002904 RCX: ffffffff81ecb160
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff9b19d340
RBP: ffffffff8e7f06c0 R08: 0000000000000001 R09: fffffbfff3633a68
R10: 0000000000000003 R11: 0000000000000000 R12: 1ffffffff1c81e50
R13: 0000000000000246 R14: 0000000000000004 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88809717d000(0063) knlGS:00000000f5456b40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 000000000c35d187 CR3: 0000000078287000 CR4: 0000000000352ef0
Call Trace:
 <IRQ>
 rcu_check_gp_start_stall kernel/rcu/tree_stall.h:1012 [inline]
 rcu_core+0x2cb/0x10d0 kernel/rcu/tree.c:2864
 handle_softirqs+0x1ea/0xa00 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x162/0x210 kernel/softirq.c:735
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1061
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x589/0x1700 kernel/smp.c:892
Code: b8 00 00 00 00 00 fc ff df 48 8b 54 24 08 49 89 d5 49 89 d4 49 c1 ed 03 41 83 e4 07 49 01 c5 41 83 c4 03 e8 09 73 0c 00 f3 90 <41> 0f b6 45 00 41 38 c4 7c 08 84 c0 0f 85 63 0f 00 00 8b 45 08 31
RSP: 0018:ffffc90003f87b28 EFLAGS: 00000246
RAX: 0000000000080000 RBX: 0000000000000001 RCX: ffffc9000d082000
RDX: 0000000000080000 RSI: ffffffff81fb74d7 RDI: ffff88802904a500
RBP: ffff88802b341080 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003
R13: ffffed1005668211 R14: 0000000000000001 R15: ffff88802b23c700
 clock_was_set+0x62b/0x870 kernel/time/hrtimer.c:999
 do_settimeofday64+0x330/0x4d0 kernel/time/timekeeping.c:1603
 do_sys_settimeofday64+0x1dc/0x260 kernel/time/time.c:195
 __do_sys_clock_settime32 kernel/time/posix-timers.c:1279 [inline]
 __se_sys_clock_settime32 kernel/time/posix-timers.c:1267 [inline]
 __ia32_sys_clock_settime32+0x1c1/0x2a0 kernel/time/posix-timers.c:1267
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xe7/0x950 arch/x86/entry/syscall_32.c:307
 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7f93fcc
Code: d2 74 05 c1 e8 0c 89 02 8b 5d fc 31 c0 c9 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 2e 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 58 b8
RSP: 002b:00000000f545650c EFLAGS: 00000292 ORIG_RAX: 0000000000000108
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000080000240
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
----------------
Code disassembly (best guess):
   0:	b8 00 00 00 00       	mov    $0x0,%eax
   5:	00 fc                	add    %bh,%ah
   7:	ff                   	lcall  (bad)
   8:	df 48 8b             	fisttps -0x75(%rax)
   b:	54                   	push   %rsp
   c:	24 08                	and    $0x8,%al
   e:	49 89 d5             	mov    %rdx,%r13
  11:	49 89 d4             	mov    %rdx,%r12
  14:	49 c1 ed 03          	shr    $0x3,%r13
  18:	41 83 e4 07          	and    $0x7,%r12d
  1c:	49 01 c5             	add    %rax,%r13
  1f:	41 83 c4 03          	add    $0x3,%r12d
  23:	e8 09 73 0c 00       	call   0xc7331
  28:	f3 90                	pause
* 2a:	41 0f b6 45 00       	movzbl 0x0(%r13),%eax <-- trapping instruction
  2f:	41 38 c4             	cmp    %al,%r12b
  32:	7c 08                	jl     0x3c
  34:	84 c0                	test   %al,%al
  36:	0f 85 63 0f 00 00    	jne    0xf9f
  3c:	8b 45 08             	mov    0x8(%rbp),%eax
  3f:	31                   	.byte 0x31