------------[ cut here ]------------ 1 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: swapper/0/0 Modules linked in: CPU: 0 UID: 0 PID: 0 Comm: swapper/0 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 03 19 9b e8 e0 33 88 00 b8 01 00 00 00 87 05 15 47 2c 19 85 c0 0f 85 3d 01 00 00 90 <0f> 0b 90 48 c7 c3 c4 71 d7 90 48 81 fd 40 07 7f 8e 74 5a 48 b8 00 RSP: 0018:ffffc90000007de8 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 0000000000002904 RCX: ffffffff81ecbc20 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff9b190340 RBP: ffffffff8e7f0740 R08: 0000000000000001 R09: fffffbfff3632068 R10: 0000000000000003 R11: 0000000000000000 R12: 1ffffffff1c81e50 R13: 0000000000000246 R14: 0000000000000200 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88809718a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000c35f967 CR3: 000000006feb6000 CR4: 0000000000352ef0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083 DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: 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 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: d6 95 02 e9 43 44 03 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 83 b0 24 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e407e00 EFLAGS: 00000206 RAX: 000000000511fc9f RBX: ffffffff8e4955c0 RCX: ffffffff8b86e225 RDX: 0000000000000000 RSI: ffffffff8df1ab41 RDI: ffffffff8c1c4580 RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed10056467b5 R10: ffff88802b233dab R11: 0000000000000000 R12: 0000000000000000 R13: fffffbfff1c92ab8 R14: 0000000000000000 R15: ffffffff90d73e50 arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline] default_idle+0x9/0x10 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x464/0x590 kernel/sched/idle.c:352 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:451 rest_init+0x251/0x260 init/main.c:762 start_kernel+0x484/0x490 init/main.c:1220 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x12b/0x130 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x148 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 95 xchg %eax,%ebp 1: 02 e9 add %cl,%ch 3: 43 rex.XB 4: 44 03 00 add (%rax),%r8d 7: 0f 1f 00 nopl (%rax) a: 90 nop b: 90 nop c: 90 nop d: 90 nop e: 90 nop f: 90 nop 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: f3 0f 1e fa endbr64 1e: eb 07 jmp 0x27 20: 0f 00 2d 83 b0 24 00 verw 0x24b083(%rip) # 0x24b0aa 27: fb sti 28: f4 hlt * 29: c3 ret <-- trapping instruction 2a: cc int3 2b: cc int3 2c: cc int3 2d: cc int3 2e: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1) 35: 00 00 00 38: 66 90 xchg %ax,%ax 3a: 90 nop 3b: 90 nop 3c: 90 nop 3d: 90 nop 3e: 90 nop