watchdog: BUG: soft lockup - CPU#1 stuck for 144s! [syz.3.491:1833]
CPU#1 Utilization every 22s during lockup:
#1: 100% system, 0% softirq, 1% hardirq, 0% idle
#2: 100% system, 1% softirq, 1% hardirq, 0% idle
#3: 100% system, 0% 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: 1 UID: 0 PID: 1833 Comm: syz.3.491 Not tainted 6.12.30-syzkaller-g88813c11dc64 #0 d54adf55d921c39fb7151a4c54847246e47052b7
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:__lookup_mnt+0xa6/0x160 fs/namespace.c:809
Code: c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 72 b4 ec ff 4d 8b 3f 4d 85 ff 74 7f 4d 8d 67 10 4c 89 e0 48 c1 e8 03 42 80 3c 28 00 <74> 08 4c 89 e7 e8 50 b4 ec ff 49 8b 04 24 48 83 c0 20 4c 39 f0 74
RSP: 0018:ffffc90010317ae8 EFLAGS: 00000246
RAX: 1ffff1102b358c02 RBX: ffff8881107ad880 RCX: 000000000000000e
RDX: ffffc900029c6000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90010317b10 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52002062f9c R12: ffff888159ac6010
R13: dffffc0000000000 R14: ffff8881570c6e20 R15: ffff888159ac6000
FS: 00007fac8e4ab6c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f19891a8f98 CR3: 000000011bdd0000 CR4: 00000000003526b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
propagate_umount+0x584/0x1650 fs/pnode.c:597
umount_tree+0x5eb/0xf70 fs/namespace.c:1780
do_umount fs/namespace.c:-1 [inline]
path_umount+0xe9a/0xf40 fs/namespace.c:2014
ksys_umount fs/namespace.c:2037 [inline]
__do_sys_umount fs/namespace.c:2042 [inline]
__se_sys_umount fs/namespace.c:2040 [inline]
__x64_sys_umount+0x126/0x170 fs/namespace.c:2040
x64_sys_call+0x2ab8/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:167
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: 0033:0x7fac8d58e9a9
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:00007fac8e4ab038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: ffffffffffffffda RBX: 00007fac8d7b6080 RCX: 00007fac8d58e9a9
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000200000000040
RBP: 00007fac8d610d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fac8d7b6080 R15: 00007ffc605f2df8
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 289 Comm: syz-executor Not tainted 6.12.30-syzkaller-g88813c11dc64 #0 d54adf55d921c39fb7151a4c54847246e47052b7
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:pv_native_safe_halt+0x17/0x20 arch/x86/kernel/paravirt.c:106
Code: cc cc cc b8 24 49 f1 2c 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 73 8c 41 00 f3 0f 1e fa 55 48 89 e5 fb f4 <5d> e9 c3 54 02 00 cc cc cc b8 00 00 00 00 90 90 90 90 90 90 90 90
RSP: 0018:ffffc9000b5ef710 EFLAGS: 000002d3
RAX: ffffffff81435565 RBX: 0000000000000003 RCX: ffff888128823900
RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000003
RBP: ffffc9000b5ef710 R08: ffffffff8720d604 R09: 1ffffffff0e41ac0
R10: dffffc0000000000 R11: fffffbfff0e41ac1 R12: dffffc0000000000
R13: 0000000000000200 R14: 0000000000000003 R15: 1ffff920016bdee4
FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb384092ff8 CR3: 00000000072a8000 CR4: 00000000003526b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
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:1415
mntput+0x63/0xd0 fs/namespace.c:1470
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+0x985/0x2630 kernel/exit.c:940
do_group_exit+0x22a/0x300 kernel/exit.c:1094
get_signal+0x139d/0x14f0 kernel/signal.c:2934
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]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x58/0xb0 kernel/entry/common.c:218
do_syscall_64+0x64/0xf0 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f79af984bd3
Code: Unable to access opcode bytes at 0x7f79af984ba9.
RSP: 002b:00007ffe28afe498 EFLAGS: 00000202 ORIG_RAX: 000000000000003d
RAX: fffffffffffffe00 RBX: 000000000000017a RCX: 00007f79af984bd3
RDX: 0000000040000000 RSI: 00007ffe28afe4dc RDI: 00000000ffffffff
RBP: 00007ffe28afe4dc R08: 000000003a1fc597 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000080
R13: 0000000000000000 R14: 000000000000f188 R15: 00007ffe28afe530