BUG: soft lockup in _do

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
linux-4.19	INFO: rcu detected stall in _do_fork	syz		error	3	838d	848d	0/1	upstream: reported syz repro on 2021/12/30 08:01
linux-4.19	BUG: soft lockup in _do_fork				1	1107d	1107d	0/1	auto-closed as invalid on 2021/08/12 22:53

watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [syz-executor.3:9532] Modules linked in: irq event stamp: 3943956 hardirqs last enabled at (3943955): [<ffffffff87400976>] restore_regs_and_return_to_kernel+0x0/0x2a hardirqs last disabled at (3943956): [<ffffffff874018ae>] apic_timer_interrupt+0x8e/0xa0 arch/x86/entry/entry_64.S:793 softirqs last enabled at (223412): [<ffffffff8760068b>] __do_softirq+0x68b/0x9ff kernel/softirq.c:314 softirqs last disabled at (217841): [<ffffffff81321cf3>] invoke_softirq kernel/softirq.c:368 [inline] softirqs last disabled at (217841): [<ffffffff81321cf3>] irq_exit+0x193/0x240 kernel/softirq.c:409 CPU: 0 PID: 9532 Comm: syz-executor.3 Not tainted 4.14.277-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff88809d32a200 task.stack: ffff88809e960000 RIP: 0010:pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:411 [inline] RIP: 0010:__pv_queued_spin_lock_slowpath+0x265/0x910 kernel/locking/qspinlock.c:465 RSP: 0018:ffff88809e967af8 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff10 RAX: 0000000000000003 RBX: ffff8880ba434f00 RCX: fffffbfff11c24dd RDX: 00000000000011a4 RSI: 0000000000000000 RDI: 0000000000000286 RBP: ffffffff88e126e8 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 R13: dffffc0000000000 R14: ffffffff88e126e9 R15: ffffed10174869e8 FS: 00007f57941a1700(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c000698000 CR3: 00000000990ac000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:669 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:52 [inline] queued_spin_lock include/asm-generic/qspinlock.h:90 [inline] do_raw_spin_lock+0x178/0x200 kernel/locking/spinlock_debug.c:113 spin_lock include/linux/spinlock.h:317 [inline] write_seqlock include/linux/seqlock.h:456 [inline] lock_mount_hash fs/mount.h:122 [inline] mntput_no_expire+0x18f/0x910 fs/namespace.c:1221 mntput+0x5c/0x80 fs/namespace.c:1272 free_fs_struct fs/fs_struct.c:89 [inline] exit_fs+0xdd/0x160 fs/fs_struct.c:107 copy_process.part.0+0x42c1/0x71c0 kernel/fork.c:2005 copy_process kernel/fork.c:1606 [inline] _do_fork+0x184/0xc80 kernel/fork.c:2092 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f579582c0e9 RSP: 002b:00007f57941a1118 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007f579593ef60 RCX: 00007f579582c0e9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000072a66000 RBP: 00007f579588608d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007ffd764b2a3f R14: 00007f57941a1300 R15: 0000000000022000 Code: 84 c0 0f 85 2e 04 00 00 48 89 e9 48 89 ee c6 45 01 01 ba 00 80 00 00 48 c1 e9 03 83 e6 07 41 b8 01 00 00 00 4c 01 e9 eb 0b f3 90 <83> ea 01 0f 84 42 04 00 00 0f b6 01 40 38 f0 7f 08 84 c0 0f 85 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 9550 Comm: syz-executor.1 Not tainted 4.14.277-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff88809963c000 task.stack: ffff888092e90000 RIP: 0010:__default_send_IPI_shortcut+0x5f/0xa0 arch/x86/kernel/apic/ipi.c:46 RSP: 0018:ffff8880ba506fe8 EFLAGS: 00000002 RAX: 00000000000400f6 RBX: 0000000000040000 RCX: 0000000000000000 RDX: 0000000000040400 RSI: 00000000000000f6 RDI: 0000000000040000 RBP: ffffffff88cca000 R08: ffff88809c228000 R09: 1ffff11013845080 R10: ffff88809c22ce2f R11: ffff88809963c000 R12: ffff888098036cf8 R13: ffffed10135f78db R14: ffff88809afbc5f0 R15: dffffc0000000000 FS: 00007efdb94b5700(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007efdb94949d0 CR3: 0000000098e96000 CR4: 00000000003406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <IRQ> arch_irq_work_raise+0xc4/0x150 arch/x86/kernel/irq_work.c:31 irq_work_queue kernel/irq_work.c:100 [inline] irq_work_queue+0x197/0x1e0 kernel/irq_work.c:87 perf_output_wakeup kernel/events/ring_buffer.c:26 [inline] perf_output_put_handle+0x270/0x410 kernel/events/ring_buffer.c:125 perf_output_end+0x11/0x90 kernel/events/ring_buffer.c:293 __perf_event_output kernel/events/core.c:6289 [inline] perf_event_output_forward+0x100/0x1f0 kernel/events/core.c:6300 __perf_event_overflow+0x113/0x310 kernel/events/core.c:7549 perf_swevent_hrtimer+0x220/0x350 kernel/events/core.c:8757 __run_hrtimer kernel/time/hrtimer.c:1223 [inline] __hrtimer_run_queues+0x30b/0xc80 kernel/time/hrtimer.c:1287 hrtimer_interrupt+0x1e6/0x5e0 kernel/time/hrtimer.c:1321 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1079 [inline] smp_apic_timer_interrupt+0x117/0x5e0 arch/x86/kernel/apic/apic.c:1104 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:793 RIP: 0010:memset_erms+0xb/0x10 arch/x86/lib/memset_64.S:67 RSP: 0018:ffff8880ba507678 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10 RAX: ffffed10174a0e00 RBX: ffff8880ba507798 RCX: 0000000000000000 RDX: 0000000000000058 RSI: 0000000000000000 RDI: ffff8880ba507780 RBP: 1ffff110174a0ed4 R08: 0000000000000001 R09: ffff8880ba507728 R10: ffff8880ba50777f R11: 0000000000000000 R12: ffff88809963c000 R13: 0000000000000000 R14: dffffc0000000000 R15: ffff8880ba507728 memset include/linux/string.h:361 [inline] __unwind_start+0x66/0x930 arch/x86/kernel/unwind_orc.c:511 unwind_start arch/x86/include/asm/unwind.h:60 [inline] __save_stack_trace+0x63/0x160 arch/x86/kernel/stacktrace.c:43 save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551 slab_post_alloc_hook mm/slab.h:442 [inline] slab_alloc mm/slab.c:3390 [inline] kmem_cache_alloc+0x111/0x3c0 mm/slab.c:3550 dst_alloc+0xed/0x6d0 net/core/dst.c:107 __ip6_dst_alloc net/ipv6/route.c:357 [inline] ip6_dst_alloc+0x39/0x2d0 net/ipv6/route.c:370 icmp6_dst_alloc+0x155/0x580 net/ipv6/route.c:1768 ndisc_send_skb+0xace/0x1390 net/ipv6/ndisc.c:463 ndisc_send_rs+0x125/0x630 net/ipv6/ndisc.c:677 addrconf_rs_timer+0x2bb/0x5a0 net/ipv6/addrconf.c:3769 call_timer_fn+0x14a/0x650 kernel/time/timer.c:1280 expire_timers+0x232/0x4d0 kernel/time/timer.c:1319 __run_timers kernel/time/timer.c:1637 [inline] run_timer_softirq+0x1d5/0x5a0 kernel/time/timer.c:1650 __do_softirq+0x24d/0x9ff kernel/softirq.c:288 invoke_softirq kernel/softirq.c:368 [inline] irq_exit+0x193/0x240 kernel/softirq.c:409 exiting_irq arch/x86/include/asm/apic.h:638 [inline] smp_apic_timer_interrupt+0x141/0x5e0 arch/x86/kernel/apic/apic.c:1106 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:793 </IRQ> RIP: 0010:disconnect_mount fs/namespace.c:1478 [inline] RIP: 0010:umount_tree+0x65f/0xb60 fs/namespace.c:1535 RSP: 0018:ffff888092e97a90 EFLAGS: 00000a02 ORIG_RAX: ffffffffffffff10 RAX: 0000000000000000 RBX: ffff88808d51ac88 RCX: ffffc90008c90000 RDX: 0000000000040000 RSI: ffffffff818dac2f RDI: ffff888099aee430 RBP: dffffc0000000000 R08: ffff88808d51aad0 R09: 0000000000000003 R10: 0000000000000000 R11: ffff88809963c000 R12: ffff888099aee400 R13: ffff888092e97ad8 R14: ffff88808d51ac00 R15: ffff88808d51ac10 drop_collected_mounts+0x96/0x160 fs/namespace.c:1886 put_mnt_ns fs/namespace.c:3345 [inline] put_mnt_ns+0x42/0x60 fs/namespace.c:3341 create_new_namespaces+0x42f/0x720 kernel/nsproxy.c:128 copy_namespaces+0x27b/0x310 kernel/nsproxy.c:165 copy_process.part.0+0x25f8/0x71c0 kernel/fork.c:1794 copy_process kernel/fork.c:1606 [inline] _do_fork+0x184/0xc80 kernel/fork.c:2092 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7efdbab400e9 RSP: 002b:00007efdb94b5118 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007efdbac52f60 RCX: 00007efdbab400e9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000072a66000 RBP: 00007efdbab9a08d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007ffeb732c22f R14: 00007efdb94b5300 R15: 0000000000022000 Code: 00 84 c0 74 04 3c 03 7e 45 8b 04 25 00 c3 5f ff f6 c4 10 75 e6 09 da 89 f0 09 d0 80 ce 04 83 fe 02 0f 44 c2 89 04 25 00 c3 5f ff <48> 83 c4 08 5b 5d c3 48 c7 c7 00 c3 5f ff 89 54 24 04 89 34 24 ---------------- Code disassembly (best guess): 0: 84 c0 test %al,%al 2: 0f 85 2e 04 00 00 jne 0x436 8: 48 89 e9 mov %rbp,%rcx b: 48 89 ee mov %rbp,%rsi e: c6 45 01 01 movb $0x1,0x1(%rbp) 12: ba 00 80 00 00 mov $0x8000,%edx 17: 48 c1 e9 03 shr $0x3,%rcx 1b: 83 e6 07 and $0x7,%esi 1e: 41 b8 01 00 00 00 mov $0x1,%r8d 24: 4c 01 e9 add %r13,%rcx 27: eb 0b jmp 0x34 29: f3 90 pause * 2b: 83 ea 01 sub $0x1,%edx <-- trapping instruction 2e: 0f 84 42 04 00 00 je 0x476 34: 0f b6 01 movzbl (%rcx),%eax 37: 40 38 f0 cmp %sil,%al 3a: 7f 08 jg 0x44 3c: 84 c0 test %al,%al 3e: 0f .byte 0xf 3f: 85 .byte 0x85