watchdog: BUG: soft lockup - CPU#0 stuck for 123s! [syz.9.2239:9421] Modules linked in: CPU: 0 PID: 9421 Comm: syz.9.2239 Tainted: G W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:163 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x10/0x60 kernel/kcov.c:197 Code: 89 fb e8 13 00 00 00 48 8b 3d 4c ba 3f 05 48 89 de e8 44 4f 39 00 5b 5d c3 00 55 48 89 e5 48 8b 45 08 65 48 8b 0d 30 c9 9e 7e <65> 8b 15 35 c9 9e 7e f7 c2 00 01 ff 00 74 11 f7 c2 00 01 00 00 74 RSP: 0018:ffffc90000cb6ef8 EFLAGS: 00000207 RAX: ffffffff83ab1465 RBX: 00000000ffff0000 RCX: ffff88811a903b40 RDX: ffff88811a903b40 RSI: 00000000ffff0000 RDI: 0000000000180000 RBP: ffffc90000cb6ef8 R08: ffff88811a903b40 R09: 0000000000000002 R10: 00000000ffffffff R11: 0000000000000000 R12: 0000000000180000 R13: dffffc0000000000 R14: ffff888134d9cc00 R15: ffff88812f590000 FS: 00007f172c6d86c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000001200 CR3: 000000010d1a8000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: qdisc_match_from_root net/sched/sch_api.c:266 [inline] qdisc_lookup+0x165/0x4e0 net/sched/sch_api.c:304 qdisc_tree_reduce_backlog+0x111/0x340 net/sched/sch_api.c:793 codel_change+0x8e7/0xbc0 net/sched/sch_codel.c:180 codel_init+0x1a8/0x390 net/sched/sch_codel.c:199 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: 0033:0x7f172dc70749 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:00007f172c6d8038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f172dec6fa0 RCX: 00007f172dc70749 RDX: 0000000000000000 RSI: 0000200000001200 RDI: 0000000000000003 RBP: 00007f172dcf4f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f172dec7038 R14: 00007f172dec6fa0 R15: 00007ffc6bc5bdc8 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3612 Comm: kworker/u4:6 Tainted: G W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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:ffffc90000c77720 EFLAGS: 00000293 RAX: ffffffff81593858 RBX: 0000000000000000 RCX: ffff88811a0f13c0 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90000c77810 R08: dffffc0000000000 R09: ffffed103ee0aec9 R10: ffffed103ee0aec9 R11: 1ffff1103ee0aec8 R12: dffffc0000000000 R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff9200018eee8 FS: 0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5f26313000 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_disable_cpuslocked+0xc5/0x1a0 kernel/jump_label.c:207 static_key_disable+0x1a/0x30 kernel/jump_label.c:215 toggle_allocation_gate+0x363/0x400 mm/kfence/core.c:638 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