rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { P194 P812 P32392 P30404 P30533 P811 P810 P808 P809 P803 P804 P759 P805 P34 P110 1-.... } 10240 jiffies s: 40353 root: 0x2/T rcu: blocking rcu_node structures (internal RCU debug): Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 785 Comm: syz.3.11047 Not tainted syzkaller #0 68071847e78a8b5e73ab1b858b320f4e6b4f981b Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 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 77 4e 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:ffffc900027279c0 EFLAGS: 00000202 RAX: 1ffff11026351f4c RBX: ffffffffffffff28 RCX: dffffc0000000000 RDX: ffffc9000b243000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc90002727a10 R08: ffff888116ae97ef R09: 0000000000000000 R10: ffff888116ae97e0 R11: ffffed1022d5d2fe R12: ffff888131a8fa40 R13: ffff88812b68e990 R14: ffff888131a8fa60 R15: ffff88814190c8c0 FS: 00007f2f5ca176c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbd4cec59c8 CR3: 0000000145084000 CR4: 00000000003526b0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083 DR3: ffffffffefffff15 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: 0033:0x7f2f5bb8eec9 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:00007f2f5ca17038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f2f5bde5fa0 RCX: 00007f2f5bb8eec9 RDX: 0000000000000000 RSI: 0000200000000100 RDI: 0000200000000000 RBP: 00007f2f5bc11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000101091 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2f5bde6038 R14: 00007f2f5bde5fa0 R15: 00007ffe14150c18