watchdog: BUG: soft lockup - CPU#0 stuck for 153s! [syz.7.8026:24470] CPU#0 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: 0 UID: 0 PID: 24470 Comm: syz.7.8026 Not tainted syzkaller #0 22de895e84cf4880b304a967638547f141894232 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:430 [inline] RIP: 0010:__pv_queued_spin_lock_slowpath+0x697/0xcc0 kernel/locking/qspinlock.c:508 Code: 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 75 4c 80 3f 00 74 08 f3 90 c3 75 dd eb 59 be 02 00 00 00 e8 d9 ed 4c fc 48 8d bc 24 90 00 RSP: 0018:ffffc9000499f9e0 EFLAGS: 00000206 RAX: 0000000000000000 RBX: 00000000ffffd682 RCX: ffff8881464ccc00 RDX: ffff8881f6e50a54 RSI: 0000000000000003 RDI: ffffffff8720d604 RBP: ffffc9000499faf0 R08: ffffffff8720d604 R09: 1ffffffff0e41ac0 R10: dffffc0000000000 R11: fffffbfff0e41ac1 R12: 0000000000000000 R13: 1ffffffff0e5cd9d R14: dffffc0000000000 R15: 1ffffffff0e41ac0 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c32c3b9 CR3: 00000000072a8000 CR4: 00000000003526b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000002009800 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 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+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 __do_sys_exit_group kernel/exit.c:1106 [inline] __se_sys_exit_group kernel/exit.c:1104 [inline] __x64_sys_exit_group+0x43/0x50 kernel/exit.c:1104 x64_sys_call+0x2ed2/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:232 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: 0033:0x7feb9c98efc9 Code: Unable to access opcode bytes at 0x7feb9c98ef9f. RSP: 002b:00007ffd2ef24cb8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007feb9c98efc9 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffd2ef24d1c R08: 0000000f2ef24daf R09: 00000000000927c0 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000011c R13: 00000000000927c0 R14: 000000000007fe40 R15: 00007ffd2ef24d70 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 24458 Comm: syz.2.8020 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:ffffc900047c79c0 EFLAGS: 00000283 RAX: 1ffff110238e98ac RBX: ffffffffffffff28 RCX: dffffc0000000000 RDX: ffffc90019f59000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc900047c7a10 R08: ffff88811c5b4d6f R09: 0000000000000000 R10: ffff88811c5b4d60 R11: ffffed10238b69ae R12: ffff88811c74c540 R13: ffff88811dcd7aa0 R14: ffff88811c74c560 R15: ffff88812c3d8700 FS: 00007fbe874666c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fcba6485f98 CR3: 000000012f61e000 CR4: 00000000003526b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000012009800 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 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: 0033:0x7fbe8658efc9 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:00007fbe87466038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fbe867e6090 RCX: 00007fbe8658efc9 RDX: 0000000000000000 RSI: 0000200000000200 RDI: 0000200000000380 RBP: 00007fbe86611f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000002125099 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fbe867e6128 R14: 00007fbe867e6090 R15: 00007ffd1b165b98