BUG: workqueue lockup - pool cpus=0 node=0 flags=0x0 nice=0 stuck for 144s! Showing busy workqueues and worker pools: workqueue events: flags=0x0 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=2 refcnt=3 pending: vmstat_shepherd, psi_avgs_work pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=4 refcnt=5 pending: 4*rht_deferred_worker workqueue events_long: flags=0x0 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: br_multicast_gc_work pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=3 refcnt=4 pending: 3*br_multicast_gc_work workqueue events_unbound: flags=0x2 pwq 8: cpus=0-1 flags=0x4 nice=0 active=3 refcnt=4 pending: toggle_allocation_gate, flush_memcg_stats_dwork, crng_reseed workqueue events_freezable: flags=0x4 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: update_balloon_stats_func workqueue events_power_efficient: flags=0x80 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=4 refcnt=5 pending: 2*neigh_managed_work, 2*neigh_periodic_work pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=3 refcnt=4 pending: wg_ratelimiter_gc_entries, gc_worker, check_lifetime workqueue mm_percpu_wq: flags=0x8 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: vmstat_update workqueue writeback: flags=0x4a pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 pending: wb_workfn workqueue kblockd: flags=0x18 pwq 7: cpus=1 node=0 flags=0x0 nice=-20 active=1 refcnt=2 pending: blk_mq_timeout_work workqueue ipv6_addrconf: flags=0x6000a pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=9 pending: addrconf_verify_work inactive: 5*addrconf_verify_work workqueue wg-crypt-wg0: flags=0x28 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=2 refcnt=3 pending: wg_packet_encrypt_worker, wg_packet_tx_worker pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker workqueue wg-kex-wg2: flags=0x6 pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 pending: wg_packet_handshake_send_worker workqueue wg-crypt-wg2: flags=0x28 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker workqueue wg-crypt-wg0: flags=0x28 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=2 refcnt=3 pending: wg_packet_encrypt_worker, wg_packet_tx_worker pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker workqueue wg-kex-wg1: flags=0x6 pwq 8: cpus=0-1 flags=0x4 nice=0 active=2 refcnt=3 pending: 2*wg_packet_handshake_send_worker workqueue wg-crypt-wg1: flags=0x28 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=2 refcnt=3 pending: wg_packet_encrypt_worker, wg_packet_tx_worker workqueue wg-kex-wg2: flags=0x6 pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 pending: wg_packet_handshake_send_worker workqueue wg-crypt-wg0: flags=0x28 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=2 refcnt=3 pending: wg_packet_encrypt_worker, wg_packet_tx_worker pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker workqueue wg-kex-wg1: flags=0x24 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_handshake_receive_worker workqueue wg-kex-wg1: flags=0x6 pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 pending: wg_packet_handshake_send_worker pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 pending: wg_packet_handshake_send_worker workqueue wg-crypt-wg1: flags=0x28 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=3 refcnt=4 pending: wg_packet_encrypt_worker, wg_packet_tx_worker, wg_packet_decrypt_worker pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker workqueue wg-kex-wg2: flags=0x6 pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 pending: wg_packet_handshake_send_worker workqueue wg-crypt-wg2: flags=0x28 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker workqueue wg-kex-wg0: flags=0x6 pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 pending: wg_packet_handshake_send_worker workqueue wg-crypt-wg0: flags=0x28 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=2 refcnt=3 pending: wg_packet_encrypt_worker, wg_packet_tx_worker pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker workqueue wg-kex-wg2: flags=0x6 pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 pending: wg_packet_handshake_send_worker workqueue wg-crypt-wg2: flags=0x28 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker workqueue wg-crypt-wg0: flags=0x28 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=2 refcnt=3 pending: wg_packet_encrypt_worker, wg_packet_tx_worker pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker workqueue wg-kex-wg1: flags=0x6 pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 pending: wg_packet_handshake_send_worker workqueue wg-kex-wg2: flags=0x6 pwq 8: cpus=0-1 flags=0x4 nice=0 active=1 refcnt=2 pending: wg_packet_handshake_send_worker workqueue wg-crypt-wg2: flags=0x28 pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=1 refcnt=2 pending: wg_packet_encrypt_worker Showing backtraces of running workers in stalled CPU-bound worker pools: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 4688 Comm: syz.4.1617 Not tainted 6.12.30-syzkaller-g2e58e85c038f #0 c5e7ad78b71ddb211d6a9cda70735ca8545dcbc5 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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 67 58 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:ffffc900149e79c0 EFLAGS: 00000287 RAX: 1ffff110210d2e34 RBX: ffffffffffffff28 RCX: dffffc0000000000 RDX: ffffc900128bf000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc900149e7a10 R08: ffff88814192a66f R09: 0000000000000000 R10: ffff88814192a660 R11: ffffed10283254ce R12: ffff888108697180 R13: ffff8881107a4770 R14: ffff8881086971a0 R15: ffff88811c0a6c40 FS: 00007f5bef7ab6c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555947774a8 CR3: 00000001461f0000 CR4: 00000000003526b0 Call Trace: umount_tree+0xdfd/0xf70 fs/namespace.c:1807 attach_recursive_mnt+0x6df/0x21c0 fs/namespace.c:2548 graft_tree+0x157/0x1c0 fs/namespace.c:2683 do_loopback+0x364/0x4b0 fs/namespace.c:2798 path_mount+0x582/0x1050 fs/namespace.c:3840 do_mount fs/namespace.c:3859 [inline] __do_sys_mount fs/namespace.c:4069 [inline] __se_sys_mount+0x2bd/0x480 fs/namespace.c:4046 __x64_sys_mount+0xc3/0xf0 fs/namespace.c:4046 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: 0033:0x7f5bf258e9a9 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:00007f5bef7ab038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f5bf27b65c0 RCX: 00007f5bf258e9a9 RDX: 0000000000000000 RSI: 0000200000000080 RDI: 0000200000000240 RBP: 00007f5bf2610ca1 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000080700a R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f5bf27b65c0 R15: 00007ffc9ff0e018 ---------------- Code disassembly (best guess): 0: 24 20 and $0x20,%al 2: 4c 89 f0 mov %r14,%rax 5: 48 c1 e8 03 shr $0x3,%rax 9: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx 10: fc ff df 13: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1) 17: 74 08 je 0x21 19: 4c 89 f7 mov %r14,%rdi 1c: e8 67 58 e7 ff call 0xffe75888 21: 4d 39 2e cmp %r13,(%r14) 24: 0f 84 8f 00 00 00 je 0xb9 * 2a: 49 81 c4 d8 00 00 00 add $0xd8,%r12 <-- trapping instruction 31: 4c 89 e0 mov %r12,%rax 34: 48 c1 e8 03 shr $0x3,%rax 38: 48 rex.W 39: b9 00 00 00 00 mov $0x0,%ecx 3e: 00 fc add %bh,%ah