watchdog: BUG: soft lockup - CPU#0 stuck for 123s! [syz.3.777:2907]
CPU#0 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, 0% softirq, 1% hardirq, 0% idle
Modules linked in:
CPU: 0 UID: 0 PID: 2907 Comm: syz.3.777 Not tainted syzkaller #0 22de895e84cf4880b304a967638547f141894232
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:do_make_slave fs/pnode.c:101 [inline]
RIP: 0010:change_mnt_propagation+0xff/0xb00 fs/pnode.c:128
Code: 51 e7 ff 4d 8b 2e 48 c7 c3 28 ff ff ff 4d 89 fc 4d 8d 74 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
RSP: 0018:ffffc9000c3c7a80 EFLAGS: 00000246
RAX: 1ffff1102777634c RBX: ffffffffffffff28 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000040000 RDI: 0000000000100000
RBP: ffffc9000c3c7ad0 R08: ffff88811e35f7ef R09: 0000000000000000
R10: ffff88811e35f7e0 R11: ffffed1023c6befe R12: ffff88813bbb1a40
R13: ffff888115ce3cc0 R14: ffff88813bbb1a60 R15: ffff88813899f180
FS: 00007ffb86dec6c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000370 CR3: 0000000101aac000 CR4: 00000000003526b0
Call Trace:
umount_tree+0xdfd/0xf70 fs/namespace.c:1803
attach_recursive_mnt+0x6df/0x21e0 fs/namespace.c:2549
do_move_mount+0x608/0x810 fs/namespace.c:3374
__do_sys_move_mount fs/namespace.c:4308 [inline]
__se_sys_move_mount+0x28b/0xad0 fs/namespace.c:4260
__x64_sys_move_mount+0xc3/0xf0 fs/namespace.c:4260
x64_sys_call+0x2342/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:430
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: 0033:0x7ffb85f8efc9
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:00007ffb86dec038 EFLAGS: 00000246 ORIG_RAX: 00000000000001ad
RAX: ffffffffffffffda RBX: 00007ffb861e5fa0 RCX: 00007ffb85f8efc9
RDX: ffffffffffffff9c RSI: 0000200000000140 RDI: 0000000000000009
RBP: 00007ffb86011f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000000180 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffb861e6038 R14: 00007ffb861e5fa0 R15: 00007ffc901f4978
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 2955 Comm: syz.2.794 Not tainted syzkaller #0 22de895e84cf4880b304a967638547f141894232
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:pv_native_safe_halt+0x17/0x20 arch/x86/kernel/paravirt.c:106
Code: cc cc cc b8 cc 07 0d 4b 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d c3 02 3a 00 f3 0f 1e fa 55 48 89 e5 fb f4 <5d> e9 d3 54 02 00 cc cc cc b8 00 00 00 00 90 90 90 90 90 90 90 90
RSP: 0018:ffffc9000d5f7670 EFLAGS: 000002d3
RAX: ffffffff81439535 RBX: 0000000000000003 RCX: ffff88811ddf9300
RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000003
RBP: ffffc9000d5f7670 R08: ffffffff8720d604 R09: 1ffffffff0e41ac0
R10: dffffc0000000000 R11: fffffbfff0e41ac1 R12: dffffc0000000000
R13: 0000000000000200 R14: 0000000000000003 R15: 1ffff92001abeed0
FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc0f73e1ff0 CR3: 0000000129224000 CR4: 00000000003526b0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:112 [inline]
kvm_wait+0x1ba/0x220 arch/x86/kernel/kvm.c:1064
pv_wait arch/x86/include/asm/paravirt.h:596 [inline]
pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:466 [inline]
__pv_queued_spin_lock_slowpath+0x78d/0xcc0 kernel/locking/qspinlock.c:508
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+0x5b/0x70 fs/namei.c:569
free_fs_struct fs/fs_struct.c:90 [inline]
exit_fs+0xe8/0x160 fs/fs_struct.c:108
do_exit+0x98d/0x2630 kernel/exit.c:949
do_group_exit+0x22a/0x300 kernel/exit.c:1095
get_signal+0x139d/0x14f0 kernel/signal.c:2933
arch_do_signal_or_restart+0x96/0x720 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
irqentry_exit_to_user_mode+0x4e/0xb0 kernel/entry/common.c:231
irqentry_exit+0x16/0x60 kernel/entry/common.c:334
exc_general_protection+0x15a/0x1f0 arch/x86/kernel/traps.c:747
asm_exc_general_protection+0x2b/0x30 arch/x86/include/asm/idtentry.h:617
RIP: 0033:0x7fc0f898efd1
Code: Unable to access opcode bytes at 0x7fc0f898efa7.
RSP: 002b:0000200000000180 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007fc0f8be5fa0 RCX: 00007fc0f898efc9
RDX: 0000000000000000 RSI: 0000200000000180 RDI: 0000000085100000
RBP: 00007fc0f8a11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007fc0f8be6038 R14: 00007fc0f8be5fa0 R15: 00007ffc9a7c1088