RBP: 00007fbd27bfdc91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbd27de1038 R14: 00007fbd27de0fa0 R15: 00007ffe5b8ba5c8
 </TASK>
watchdog: BUG: soft lockup - CPU#0 stuck for 266s! [syz.4.161:843]
Modules linked in:
CPU: 0 PID: 843 Comm: syz.4.161 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x0/0x90 kernel/kcov.c:292
Code: 44 02 08 03 00 00 00 4a 89 7c 02 10 4a 89 74 02 18 4a 89 44 02 20 48 ff c1 48 89 0a 5d c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 <55> 48 89 e5 48 8b 45 08 65 48 8b 0d e0 a2 98 7e 65 8b 15 e1 a2 98
RSP: 0018:ffffc90000d06e80 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00000000ffff0000 RCX: ffff8881112562c0
RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000d06eb8 R08: ffff8881112562c0 R09: 0000000000000002
R10: 00000000ffffffff R11: 0000000000000002 R12: 0000000000000050
R13: dffffc0000000000 R14: ffff88812795bc00 R15: ffff88811fa92000
FS:  00007fbd265c26c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000003340 CR3: 000000012e0cb000 CR4: 00000000003506b0
Call Trace:
 <TASK>
 qdisc_tree_reduce_backlog+0x111/0x340 net/sched/sch_api.c:784
 fq_codel_change+0xa8a/0xf70 net/sched/sch_fq_codel.c:436
 fq_codel_init+0x342/0xa20 net/sched/sch_fq_codel.c:473
 qdisc_create+0x803/0x11b0 net/sched/sch_api.c:1256
 tc_modify_qdisc+0x8ad/0x1570 net/sched/sch_api.c:-1
 rtnetlink_rcv_msg+0xa4b/0xce0 net/core/rtnetlink.c:5650
 netlink_rcv_skb+0x1f5/0x440 net/netlink/af_netlink.c:2511
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5668
 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline]
 netlink_unicast+0x876/0xa40 net/netlink/af_netlink.c:1348
 netlink_sendmsg+0x879/0xb80 net/netlink/af_netlink.c:1922
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 ____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2435
 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2489
 __sys_sendmsg net/socket.c:2518 [inline]
 __do_sys_sendmsg net/socket.c:2527 [inline]
 __se_sys_sendmsg net/socket.c:2525 [inline]
 __x64_sys_sendmsg+0x206/0x2f0 net/socket.c:2525
 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: 0033:0x7fbd27b67819
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:00007fbd265c2028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fbd27de0fa0 RCX: 00007fbd27b67819
RDX: 0000000000008840 RSI: 0000200000000740 RDI: 0000000000000007
RBP: 00007fbd27bfdc91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbd27de1038 R14: 00007fbd27de0fa0 R15: 00007ffe5b8ba5c8
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 407 Comm: kworker/u4:4 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:440 [inline]
RIP: 0010:smp_call_function_many_cond+0x8e3/0xa10 kernel/smp.c:969
Code: 84 c0 0f 85 9d 00 00 00 41 8b 1f 89 de 83 e6 01 31 ff e8 e0 4e 0a 00 83 e3 01 48 8b 5c 24 10 75 07 e8 21 4b 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:ffffc90001267860 EFLAGS: 00000293
RAX: ffffffff815f7be5 RBX: ffff8881f7138e80 RCX: ffff888112c43b40
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90001267978 R08: ffff8881f7038ec7 R09: 1ffff1103ee071d8
R10: dffffc0000000000 R11: ffffed103ee071d9 R12: 1ffff1103ee271d0
R13: 1ffff1103ee07af9 R14: 0000000000000000 R15: ffff8881f703d7c8
FS:  0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055c4014c9af8 CR3: 000000000660f000 CR4: 00000000003506a0
Call Trace:
 <TASK>
 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+0x37c/0x3a0 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+0x6be/0xba0 kernel/workqueue.c:2325
 worker_thread+0xa59/0x1200 kernel/workqueue.c:2472
 kthread+0x411/0x500 kernel/kthread.c:337
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>