RBP: 00007f31cee32e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f31cf016038 R14: 00007f31cf015fa0 R15: 00007fff03bff0c8 watchdog: BUG: soft lockup - CPU#0 stuck for 284s! [syz.9.808:3279] Modules linked in: CPU: 0 PID: 3279 Comm: syz.9.808 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:qdisc_dev include/net/sch_generic.h:573 [inline] RIP: 0010:qdisc_match_from_root net/sched/sch_api.c:264 [inline] RIP: 0010:qdisc_lookup_rcu+0x279/0x4d0 net/sched/sch_api.c:330 Code: 00 00 49 83 c6 18 4c 89 f0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 f7 e8 05 56 ad fd 4d 8b 36 4d 8d 7e 40 4c 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 ff e8 e8 55 ad fd 4d 8b 3f 4c 89 f8 48 RSP: 0018:ffffc90000e66e08 EFLAGS: 00000a06 RAX: 1ffff110229b9f88 RBX: 00000000ffff0000 RCX: 0000000000080000 RDX: ffffc90003e84000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc90000e66e38 R08: 1ffff1102741e012 R09: 1ffff1102741e001 R10: dffffc0000000000 R11: fffff520001ccdc4 R12: 0000000000000000 R13: dffffc0000000000 R14: ffff888114dcfc00 R15: ffff888114dcfc40 FS: 00007f31cfb706c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c26e4c1 CR3: 000000013c3f3000 CR4: 00000000003526b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: qdisc_tree_reduce_backlog+0x10b/0x3a0 net/sched/sch_api.c:792 fq_codel_change+0xb3e/0x1080 net/sched/sch_fq_codel.c:440 fq_codel_init+0x381/0xab0 net/sched/sch_fq_codel.c:477 qdisc_create+0x89b/0x1180 net/sched/sch_api.c:1306 tc_modify_qdisc+0x924/0x19c0 net/sched/sch_api.c:-1 rtnetlink_rcv_msg+0xb28/0xde0 net/core/rtnetlink.c:6153 netlink_rcv_skb+0x200/0x450 net/netlink/af_netlink.c:2521 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:6171 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x8c1/0xa60 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x8b9/0xbd0 net/netlink/af_netlink.c:1873 sock_sendmsg_nosec net/socket.c:716 [inline] __sock_sendmsg net/socket.c:728 [inline] ____sys_sendmsg+0x5fb/0x9c0 net/socket.c:2508 ___sys_sendmsg+0x2a2/0x360 net/socket.c:2562 __sys_sendmsg net/socket.c:2591 [inline] __do_sys_sendmsg net/socket.c:2600 [inline] __se_sys_sendmsg net/socket.c:2598 [inline] __x64_sys_sendmsg+0x20d/0x2e0 net/socket.c:2598 x64_sys_call+0x171/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f31ced9ce59 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:00007f31cfb70028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f31cf015fa0 RCX: 00007f31ced9ce59 RDX: 0000000000008840 RSI: 0000200000000740 RDI: 0000000000000003 RBP: 00007f31cee32e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f31cf016038 R14: 00007f31cf015fa0 R15: 00007fff03bff0c8 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] NMI backtrace for cpu 1 skipped: idling at default_idle+0xf/0x20 arch/x86/kernel/process.c:741