watchdog: BUG: soft lockup - CPU#1 stuck for 285s! [syz.2.1692:6470]
Modules linked in:
CPU: 1 PID: 6470 Comm: syz.2.1692 Tainted: G        W         syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:qdisc_match_from_root net/sched/sch_api.c:267 [inline]
RIP: 0010:qdisc_lookup+0x2f5/0x4d0 net/sched/sch_api.c:309
Code: ff e8 7f 0e 8f fd 41 83 e7 01 75 77 4d 8d 7e 38 4c 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 c2 01 00 00 45 8b 3f 44 89 ff <89> de e8 24 0c 8f fd 41 39 df 75 54 e8 9a 0a 8f fd e9 06 01 00 00
RSP: 0018:ffffc900010c6ea8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00000000ffff0000 RCX: ffff888144de62c0
RDX: 0000000000000002 RSI: 0000000000000000 RDI: 00000000ffff0000
RBP: ffffc900010c6ed8 R08: 1ffff1102835d612 R09: 1ffff1102835d601
R10: dffffc0000000000 R11: fffff52000218dd8 R12: ffff888107390000
R13: dffffc0000000000 R14: ffff888116fad800 R15: 00000000ffff0000
FS:  00007fe8ffeef6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000001185f8000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 qdisc_tree_reduce_backlog+0x10b/0x380 net/sched/sch_api.c:784
 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:5662
 netlink_rcv_skb+0x1e9/0x430 net/netlink/af_netlink.c:2516
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5680
 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: 0033:0x7fe9014960d9
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:00007fe8ffeef028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fe90171dfa0 RCX: 00007fe9014960d9
RDX: 0000000024000800 RSI: 00002000000012c0 RDI: 0000000000000008
RBP: 00007fe90152d024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe90171e038 R14: 00007fe90171dfa0 R15: 00007ffd37dd6828
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 0 skipped: idling at default_idle+0xf/0x20 arch/x86/kernel/process.c:729