RBP: 00007f1387008e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f13871cd038 R14: 00007f13871ccfa0 R15: 00007ffc089bc598 watchdog: BUG: soft lockup - CPU#0 stuck for 123s! [syz.4.1177:4808] Modules linked in: CPU: 0 PID: 4808 Comm: syz.4.1177 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2025 RIP: 0010:qdisc_tree_reduce_backlog+0x122/0x340 net/sched/sch_api.c:791 Code: 4c 89 f7 e8 70 aa f2 fd 49 8b 3e 44 89 e6 81 e6 00 00 ff ff e8 0f da ff ff 48 85 c0 0f 84 03 02 00 00 49 89 c5 31 ff 8b 75 d0 a9 c0 b8 fd 4d 8d 75 18 4c 89 f0 48 c1 e8 03 80 3c 18 00 74 08 RSP: 0018:ffffc90000d46f28 EFLAGS: 00000246 RAX: ffff888126c7b000 RBX: dffffc0000000000 RCX: 0000000000080000 RDX: ffffc90003523000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000d46f70 R08: ffff888111c20000 R09: 0000000000000002 R10: 00000000ffffffff R11: 0000000000000002 R12: 00000000fffffff1 R13: ffff888126c7b000 R14: ffff88810f00b400 R15: ffff888126c7b040 FS: 00007f13859ee6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f37b0a1f000 CR3: 0000000133d7b000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: fq_change+0xb9e/0x10a0 net/sched/sch_fq.c:915 fq_init+0x3e3/0x5d0 net/sched/sch_fq.c:963 qdisc_create+0x780/0x1040 net/sched/sch_api.c:1265 tc_modify_qdisc+0x8da/0x14c0 net/sched/sch_api.c:1725 rtnetlink_rcv_msg+0x9db/0xb90 net/core/rtnetlink.c:5610 netlink_rcv_skb+0x1e0/0x430 net/netlink/af_netlink.c:2503 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5628 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x876/0xa40 net/netlink/af_netlink.c:1340 netlink_sendmsg+0x88d/0xb30 net/netlink/af_netlink.c:1914 sock_sendmsg_nosec net/socket.c:652 [inline] __sock_sendmsg net/socket.c:664 [inline] ____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2376 ___sys_sendmsg+0x1f0/0x260 net/socket.c:2430 __sys_sendmsg net/socket.c:2459 [inline] __do_sys_sendmsg net/socket.c:2468 [inline] __se_sys_sendmsg net/socket.c:2466 [inline] __x64_sys_sendmsg+0x1e2/0x2a0 net/socket.c:2466 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f1386f85ba9 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:00007f13859ee038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f13871ccfa0 RCX: 00007f1386f85ba9 RDX: 0000000000000000 RSI: 0000200000001200 RDI: 0000000000000006 RBP: 00007f1387008e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f13871cd038 R14: 00007f13871ccfa0 R15: 00007ffc089bc598 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 49 Comm: kworker/u4:2 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:229 [inline] RIP: 0010:smp_call_function_single+0x1f5/0x470 kernel/smp.c:517 Code: 48 44 89 f6 83 e6 01 31 ff e8 c7 6f 0a 00 41 83 e6 01 49 bc 00 00 00 00 00 fc ff df 75 0a e8 02 6c 0a 00 e9 a9 00 00 00 f3 90 44 24 48 01 00 00 00 0f 84 94 00 00 00 e8 e8 6b 0a 00 eb e9 e8 RSP: 0018:ffffc900009e7720 EFLAGS: 00000293 RAX: ffffffff81593788 RBX: 0000000000000000 RCX: ffff888109ae8000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900009e7810 R08: dffffc0000000000 R09: ffffed103ee0aec9 R10: ffffed103ee0aec9 R11: 1ffff1103ee0aec8 R12: dffffc0000000000 R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff9200013cee8 FS: 0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc51a9edfc CR3: 000000000620f000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: smp_call_function_many_cond+0x8f2/0x9e0 kernel/smp.c:653 smp_call_function_many kernel/smp.c:716 [inline] smp_call_function kernel/smp.c:738 [inline] on_each_cpu+0xab/0x170 kernel/smp.c:837 text_poke_sync arch/x86/kernel/alternative.c:1568 [inline] text_poke_bp_batch+0x1c4/0x580 arch/x86/kernel/alternative.c:1768 text_poke_flush arch/x86/kernel/alternative.c:1959 [inline] text_poke_finish+0x1a/0x30 arch/x86/kernel/alternative.c:1966 arch_jump_label_transform_apply+0x15/0x30 arch/x86/kernel/jump_label.c:126 __jump_label_update+0x37c/0x3a0 kernel/jump_label.c:459 jump_label_update+0x34c/0x3e0 kernel/jump_label.c:825 static_key_enable_cpuslocked+0x126/0x240 kernel/jump_label.c:177 static_key_enable+0x1a/0x30 kernel/jump_label.c:190 toggle_allocation_gate+0xb4/0x400 mm/kfence/core.c:624 process_one_work+0x6e1/0xba0 kernel/workqueue.c:2301 worker_thread+0xa6a/0x13b0 kernel/workqueue.c:2447 kthread+0x346/0x3d0 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298