NMI watchdog: BUG: soft lockup - CPU#1 stuck for 134s! [syz-executor7:3886]
Modules linked in:
irq event stamp: 3427268
hardirqs last  enabled at (3427267): [<ffffffff838c3329>] restore_regs_and_iret+0x0/0x1d
hardirqs last disabled at (3427268): [<ffffffff838c428b>] apic_timer_interrupt+0x9b/0xb0 arch/x86/entry/entry_64.S:741
softirqs last  enabled at (3427266): [<ffffffff838c5e9f>] __do_softirq+0x4df/0xa1a kernel/softirq.c:299
softirqs last disabled at (3427261): [<ffffffff8113f8ad>] invoke_softirq kernel/softirq.c:350 [inline]
softirqs last disabled at (3427261): [<ffffffff8113f8ad>] irq_exit+0x10d/0x140 kernel/softirq.c:391
CPU: 1 PID: 3886 Comm: syz-executor7 Not tainted 4.4.138-gcf21a9a #64
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d9519800 task.stack: ffff8800a6a18000
RIP: 0010:[<ffffffff815b4139>]  [<ffffffff815b4139>] skip_propagation_subtree fs/pnode.c:179 [inline]
RIP: 0010:[<ffffffff815b4139>]  [<ffffffff815b4139>] propagate_umount+0x2e9/0xdb0 fs/pnode.c:581
RSP: 0018:ffff8800a6a1fb70  EFLAGS: 00000286
RAX: 1ffff1001652dddd RBX: ffff8800b296f800 RCX: 000000000000000e
RDX: 0000000000000000 RSI: ffffffff815b4118 RDI: ffff8800b296eee8
RBP: ffff8800a6a1fcf0 R08: ffff8800a6a1fc88 R09: 0000000000000000
R10: 0000000000000001 R11: ffff8801d9519800 R12: ffff8800bb1a92c0
R13: ffff8800b296f908 R14: ffff8800b296ee00 R15: dffffc0000000000
FS:  0000000001400940(0063) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa9787d0c88 CR3: 00000000a6f7d000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffed003b2a341b ffff8800b5f05218 ffff8800a6a1fd58 1ffff10014d43f7d
 ffff8800a6a1fc88 ffff8800b7a4ee00 ffffed0016be0a43 ffff8800a6a1fd50
 ffff8801caab5600 ffff8801caab5630 ffff8800a6a1fc48 ffff8800ba1ce420
Call Trace:
 [<ffffffff8157f0c5>] umount_tree+0x695/0x810 fs/namespace.c:1471
 [<ffffffff8158319c>] do_umount+0x31c/0x830 fs/namespace.c:1585
 [<ffffffff8158581f>] SYSC_umount fs/namespace.c:1684 [inline]
 [<ffffffff8158581f>] SyS_umount+0x2ff/0x3f0 fs/namespace.c:1653
 [<ffffffff838c2725>] entry_SYSCALL_64_fastpath+0x22/0x9e
Code: e9 7c fe ff ff e8 98 d3 d9 ff 49 8d be e8 00 00 00 48 89 f8 48 c1 e8 03 42 80 3c 38 00 0f 85 30 0a 00 00 49 83 be e8 00 00 00 00 <0f> 84 a1 03 00 00 e8 6c d3 d9 ff 49 8d 9e c0 00 00 00 48 89 d8 
Sending NMI to other CPUs:
NMI backtrace for cpu 0
CPU: 0 PID: 23207 Comm: udevd Not tainted 4.4.138-gcf21a9a #64
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8800ae4b4800 task.stack: ffff88009cf40000
RIP: 0010:[<ffffffff81547701>]  [<ffffffff81547701>] rep_nop arch/x86/include/asm/processor.h:562 [inline]
RIP: 0010:[<ffffffff81547701>]  [<ffffffff81547701>] cpu_relax arch/x86/include/asm/processor.h:567 [inline]
RIP: 0010:[<ffffffff81547701>]  [<ffffffff81547701>] __read_seqcount_begin include/linux/seqlock.h:114 [inline]
RIP: 0010:[<ffffffff81547701>]  [<ffffffff81547701>] raw_read_seqcount_begin include/linux/seqlock.h:147 [inline]
RIP: 0010:[<ffffffff81547701>]  [<ffffffff81547701>] read_seqcount_begin include/linux/seqlock.h:164 [inline]
RIP: 0010:[<ffffffff81547701>]  [<ffffffff81547701>] read_seqbegin include/linux/seqlock.h:430 [inline]
RIP: 0010:[<ffffffff81547701>]  [<ffffffff81547701>] path_init+0x1331/0x1910 fs/namei.c:2052
RSP: 0018:ffff88009cf479e0  EFLAGS: 00000293
RAX: ffff8800ae4b4800 RBX: ffff88009cf47cf0 RCX: ffffffff844095c0
RDX: 0000000000000000 RSI: ffffffff815476ff RDI: 0000000000000246
RBP: ffff88009cf47a80 R08: ffffffff85348370 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: fffffbfff08812b8
R13: ffffffff844095c0 R14: 0000000000000041 R15: ffff8801bf85b31c
FS:  00007f48a47897a0(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f48a414b3c0 CR3: 00000000b6eaa000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff8154be69 ffffffff8596c200 ffff8800ae4b4800 ffff88009cf47a20
 ffffffff812273ad ffff8800aea3b678 ffff8800aea3b6b8 ffffffff83ab4fa0
 ffff88009cf47a50 ffffffff8122549a ffff8800aea3b600 ffff88009cf47d28
Call Trace:
 [<ffffffff8154be69>] path_openat+0x159/0x3a10 fs/namei.c:3353
 [<ffffffff81552437>] do_filp_open+0x197/0x270 fs/namei.c:3393
 [<ffffffff8151ba7c>] do_sys_open+0x31c/0x610 fs/open.c:1038
 [<ffffffff8151bd9d>] SYSC_open fs/open.c:1056 [inline]
 [<ffffffff8151bd9d>] SyS_open+0x2d/0x40 fs/open.c:1051
 [<ffffffff838c2725>] entry_SYSCALL_64_fastpath+0x22/0x9e
Code: ed ff ff e8 b2 21 fb ff e9 ba ed ff ff 48 b8 00 00 00 00 00 fc ff df 49 89 cc 49 89 cd 49 c1 ec 03 49 01 c4 e8 b1 9d e0 ff f3 90 <41> 0f b6 04 24 84 c0 74 08 3c 03 0f 8e 50 04 00 00 41 8b 45 00