RBP: 00007f363511d00c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f363530e128 R14: 00007f363530e090 R15: 00007ffc362346f8 watchdog: BUG: soft lockup - CPU#1 stuck for 286s! [syz.0.178:907] Modules linked in: CPU: 1 PID: 907 Comm: syz.0.178 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:qdisc_tree_reduce_backlog+0x14e/0x380 net/sched/sch_api.c:789 Code: 18 4c 89 f0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 f7 e8 d5 56 ce fd 4d 8b 36 49 83 c6 08 4c 89 f0 48 c1 e8 03 42 80 3c 28 00 <74> 08 4c 89 f7 e8 b8 56 ce fd 4d 89 e7 85 db 74 07 e8 3c e7 8e fd RSP: 0018:ffffc900011aeee8 EFLAGS: 00000246 RAX: 1ffffffff0dd36fc RBX: 0000000000000000 RCX: ffff888114cd0000 RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900011aef30 R08: 1ffff1102531f892 R09: 1ffff1102531f881 R10: dffffc0000000000 R11: fffff52000235dd8 R12: ffff888111286800 R13: dffffc0000000000 R14: ffffffff86e9b7e0 R15: ffff888111286840 FS: 00007f3633abe6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3633abdff8 CR3: 00000001232dc000 CR4: 00000000003506a0 Call Trace: fq_codel_change+0xa89/0xf60 net/sched/sch_fq_codel.c:436 fq_codel_init+0x33f/0xa40 net/sched/sch_fq_codel.c:473 qdisc_create+0x807/0x11a0 net/sched/sch_api.c:1256 tc_modify_qdisc+0x8ce/0x1550 net/sched/sch_api.c:-1 rtnetlink_rcv_msg+0x9fd/0xcb0 net/core/rtnetlink.c:5654 netlink_rcv_skb+0x1e9/0x430 net/netlink/af_netlink.c:2516 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5672 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline] netlink_unicast+0x86c/0xa30 net/netlink/af_netlink.c:1348 netlink_sendmsg+0x879/0xb80 net/netlink/af_netlink.c:1927 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] ____sys_sendmsg+0x5be/0x8f0 net/socket.c:2436 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2490 __sys_sendmsg net/socket.c:2519 [inline] __do_sys_sendmsg net/socket.c:2528 [inline] __se_sys_sendmsg net/socket.c:2526 [inline] __x64_sys_sendmsg+0x201/0x2d0 net/socket.c:2526 x64_sys_call+0x4b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f3635086019 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f3633abe028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f363530e090 RCX: 00007f3635086019 RDX: 0000000000008840 RSI: 0000200000000740 RDI: 0000000000000008 RBP: 00007f363511d00c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f363530e128 R14: 00007f363530e090 R15: 00007ffc362346f8 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 708 Comm: kworker/u4:5 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:440 [inline] RIP: 0010:smp_call_function_many_cond+0x8ad/0x9e0 kernel/smp.c:969 Code: 0f b6 44 05 00 84 c0 0f 85 9b 00 00 00 41 8b 1f 89 de 83 e6 01 31 ff e8 31 48 0a 00 83 e3 01 75 07 e8 77 44 0a 00 eb 42 f3 90 <48> b8 00 00 00 00 00 fc ff df 41 0f b6 44 05 00 84 c0 75 10 41 f7 RSP: 0018:ffffc90000d07860 EFLAGS: 00000293 RAX: ffffffff815f728f RBX: 0000000000000001 RCX: ffff88811c153b40 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90000d07978 R08: ffff8881f7038e97 R09: 1ffff1103ee071d2 R10: dffffc0000000000 R11: ffffed103ee071d3 R12: ffff8881f7038e80 R13: 1ffff1103ee2784d R14: 0000000000000001 R15: ffff8881f713c268 FS: 0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f954f288f33 CR3: 000000000660f000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x43/0x80 kernel/smp.c:1134 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1442 [inline] text_poke_bp_batch+0x1d4/0x600 arch/x86/kernel/alternative.c:1642 text_poke_flush arch/x86/kernel/alternative.c:1833 [inline] text_poke_finish+0x1a/0x30 arch/x86/kernel/alternative.c:1840 arch_jump_label_transform_apply+0x15/0x30 arch/x86/kernel/jump_label.c:146 __jump_label_update+0x38f/0x3b0 kernel/jump_label.c:459 jump_label_update+0x39b/0x450 kernel/jump_label.c:830 static_key_enable_cpuslocked+0x126/0x240 kernel/jump_label.c:177 static_key_enable+0x1a/0x30 kernel/jump_label.c:190 toggle_allocation_gate+0xba/0x440 mm/kfence/core.c:783 process_one_work+0x6c8/0xbb0 kernel/workqueue.c:2328 worker_thread+0xaa0/0x1250 kernel/workqueue.c:2475 kthread+0x3f5/0x4f0 kernel/kthread.c:337 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287