watchdog: BUG: soft lockup - CPU#1 stuck for 143s! [syz.5.6841:20723]
CPU#1 Utilization every 22s during lockup:
#1: 100% system, 1% softirq, 1% hardirq, 0% idle
#2: 100% system, 1% softirq, 1% hardirq, 0% idle
#3: 100% system, 1% softirq, 1% hardirq, 0% idle
#4: 100% system, 1% softirq, 1% hardirq, 0% idle
#5: 100% system, 1% softirq, 1% hardirq, 0% idle
Modules linked in:
CPU: 1 UID: 0 PID: 20723 Comm: syz.5.6841 Not tainted syzkaller #0 22de895e84cf4880b304a967638547f141894232
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:trylock_clear_pending kernel/locking/qspinlock_paravirt.h:122 [inline]
RIP: 0010:pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:431 [inline]
RIP: 0010:__pv_queued_spin_lock_slowpath+0x678/0xcc0 kernel/locking/qspinlock.c:508
Code: 48 8b 44 24 40 42 0f b6 04 30 84 c0 0f 85 3d 01 00 00 c6 02 00 43 0f b6 04 37 84 c0 0f 85 51 01 00 00 c6 03 01 bb 00 80 ff ff <66> c7 84 24 90 00 00 00 00 01 48 8b 44 24 28 42 0f b6 04 30 84 c0
RSP: 0018:ffffc900011af6a0 EFLAGS: 00000292
RAX: 0000000000000000 RBX: 00000000ffffbbd0 RCX: 0000000000080000
RDX: ffff8881f6f50a54 RSI: 0000000000022e92 RDI: ffffffff8720d604
RBP: ffffc900011af7b0 R08: ffffffff8720d604 R09: 1ffffffff0e41ac0
R10: dffffc0000000000 R11: fffffbfff0e41ac1 R12: 0000000000000000
R13: 1ffffffff0e5cd9d R14: dffffc0000000000 R15: 1ffffffff0e41ac0
FS: 00007f22ea0cf6c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000004000 CR3: 00000001146e8000 CR4: 00000000003526b0
Call Trace:
pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:584 [inline]
queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
do_raw_spin_lock include/linux/spinlock.h:187 [inline]
__raw_spin_lock include/linux/spinlock_api_smp.h:134 [inline]
_raw_spin_lock+0x109/0x120 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
write_seqlock include/linux/seqlock.h:876 [inline]
lock_mount_hash fs/namespace.c:215 [inline]
mntput_no_expire+0x147/0x6c0 fs/namespace.c:1411
mntput+0x63/0xd0 fs/namespace.c:1466
path_put fs/namei.c:569 [inline]
terminate_walk+0x1d6/0x580 fs/namei.c:692
path_openat+0x2a7f/0x34b0 fs/namei.c:3934
do_filp_open+0x1c6/0x3e0 fs/namei.c:3960
do_sys_openat2+0x12c/0x1c0 fs/open.c:1438
do_sys_open fs/open.c:1453 [inline]
__do_sys_openat fs/open.c:1469 [inline]
__se_sys_openat fs/open.c:1464 [inline]
__x64_sys_openat+0x13a/0x170 fs/open.c:1464
x64_sys_call+0xe69/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:258
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f22e918efc9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f22ea0cf038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f22e93e5fa0 RCX: 00007f22e918efc9
RDX: 0000000000080004 RSI: 0000200000000000 RDI: ffffffffffffff9c
RBP: 00007f22e9211f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000006 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f22e93e6038 R14: 00007f22e93e5fa0 R15: 00007ffde732b6c8
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 20713 Comm: syz.7.6837 Not tainted syzkaller #0 22de895e84cf4880b304a967638547f141894232
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:next_peer fs/pnode.c:19 [inline]
RIP: 0010:do_make_slave fs/pnode.c:100 [inline]
RIP: 0010:change_mnt_propagation+0x112/0xb00 fs/pnode.c:128
Code: 24 20 4c 89 f0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 4c 89 f7 e8 47 51 e7 ff 4d 39 2e 0f 84 8f 00 00 00 <49> 81 c4 d8 00 00 00 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc
RSP: 0018:ffffc9000172f9c0 EFLAGS: 00000287
RAX: 1ffff1102a0a1b4c RBX: ffffffffffffff28 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000040000 RDI: 0000000000100000
RBP: ffffc9000172fa10 R08: ffff88813b90466f R09: 0000000000000000
R10: ffff88813b904660 R11: ffffed10277208ce R12: ffff88815050da40
R13: ffff8881428d3110 R14: ffff88815050da60 R15: ffff888127a84540
FS: 00007f65dd7f86c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fab53811000 CR3: 00000001220a4000 CR4: 00000000003526b0
Call Trace:
umount_tree+0xdfd/0xf70 fs/namespace.c:1803
attach_recursive_mnt+0x6df/0x21e0 fs/namespace.c:2549
graft_tree+0x157/0x1c0 fs/namespace.c:2684
do_loopback+0x364/0x4b0 fs/namespace.c:2816
path_mount+0x582/0x1050 fs/namespace.c:3858
do_mount fs/namespace.c:3877 [inline]
__do_sys_mount fs/namespace.c:4087 [inline]
__se_sys_mount+0x2bd/0x480 fs/namespace.c:4064
__x64_sys_mount+0xc3/0xf0 fs/namespace.c:4064
x64_sys_call+0x2021/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:166
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f65dc98efc9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f65dd7f8038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f65dcbe5fa0 RCX: 00007f65dc98efc9
RDX: 0000000000000000 RSI: 0000200000000300 RDI: 0000200000000380
RBP: 00007f65dca11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000002125099 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f65dcbe6038 R14: 00007f65dcbe5fa0 R15: 00007ffc2ff641e8