watchdog: BUG: soft lockup - CPU#0 stuck for 123s! [syz.5.3018:9220]
Modules linked in:
CPU: 0 PID: 9220 Comm: syz.5.3018 Tainted: G        W         syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:check_kcov_mode kernel/kcov.c:174 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:218 [inline]
RIP: 0010:__sanitizer_cov_trace_cmp4+0x36/0x90 kernel/kcov.c:258
Code: 20 b6 9d 7e 65 8b 0d 25 b6 9d 7e f7 c1 00 01 ff 00 74 11 f7 c1 00 01 00 00 74 5b 83 ba dc 0a 00 00 00 74 52 8b 8a b8 0a 00 00 <83> f9 03 75 47 48 8b 8a c0 0a 00 00 44 8b 8a bc 0a 00 00 49 c1 e1
RSP: 0018:ffffc90000d06eb8 EFLAGS: 00000246
RAX: ffffffff83b26b8d RBX: 00000000ffff0000 RCX: 0000000000000002
RDX: ffff88814665a780 RSI: 00000000ffff0000 RDI: 00000000000a0000
RBP: ffffc90000d06eb8 R08: ffff88814665a780 R09: 0000000000000002
R10: 00000000ffffffff R11: 0000000000000002 R12: 00000000000a0000
R13: dffffc0000000000 R14: ffff888126301400 R15: ffff8881196aa000
FS:  00007ff3a96266c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000005bc040 CR3: 000000010cda5000 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:267 [inline]
 qdisc_lookup+0xed/0x4e0 net/sched/sch_api.c:304
 qdisc_tree_reduce_backlog+0x111/0x340 net/sched/sch_api.c:783
 fq_codel_change+0xa6e/0xeb0 net/sched/sch_fq_codel.c:436
 fq_codel_init+0x342/0xa20 net/sched/sch_fq_codel.c:473
 qdisc_create+0x848/0x1220 net/sched/sch_api.c:1255
 tc_modify_qdisc+0x8a1/0x1490 net/sched/sch_api.c:-1
 rtnetlink_rcv_msg+0xa31/0xcc0 net/core/rtnetlink.c:5610
 netlink_rcv_skb+0x1f5/0x440 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+0x89c/0xb50 net/netlink/af_netlink.c:1914
 sock_sendmsg_nosec net/socket.c:652 [inline]
 __sock_sendmsg net/socket.c:664 [inline]
 ____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2376
 ___sys_sendmsg+0x236/0x2e0 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+0x1f9/0x2c0 net/socket.c:2466
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7ff3aabc9eb9
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:00007ff3a9626028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ff3aae44fa0 RCX: 00007ff3aabc9eb9
RDX: 0000000000000000 RSI: 0000200000000180 RDI: 0000000000000003
RBP: 00007ff3aac37c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff3aae45038 R14: 00007ff3aae44fa0 R15: 00007fffe43a3358
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 378 Comm: kworker/u4:4 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+0x211/0x490 kernel/smp.c:517
Code: ff e8 13 88 0a 00 41 83 e6 01 49 bc 00 00 00 00 00 fc ff df 75 0a e8 4e 84 0a 00 e9 a4 00 00 00 f3 90 f7 44 24 48 01 00 00 00 <0f> 84 8f 00 00 00 e8 34 84 0a 00 eb e9 e8 fd 32 23 03 89 c3 41 89
RSP: 0018:ffffc90001497720 EFLAGS: 00000202
RAX: ffffffff815a319c RBX: 0000000000000000 RCX: ffff888110e93b40
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90001497810 R08: ffff8881f7057647 R09: 1ffff1103ee0aec8
R10: dffffc0000000000 R11: ffffed103ee0aec9 R12: dffffc0000000000
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff92000292ee8
FS:  0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa41dedae20 CR3: 000000000640f000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 smp_call_function_many_cond+0x90a/0xa00 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/0x180 kernel/smp.c:837
 text_poke_sync arch/x86/kernel/alternative.c:1568 [inline]
 text_poke_bp_batch+0x1cb/0x5f0 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+0xba/0x440 mm/kfence/core.c:624
 process_one_work+0x6e1/0xba0 kernel/workqueue.c:2301
 worker_thread+0xa6a/0x13c0 kernel/workqueue.c:2447
 kthread+0x346/0x3d0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298