watchdog: BUG: soft lockup - CPU#1 stuck for 123s! [syz.0.1057:4135]
Modules linked in:
CPU: 1 PID: 4135 Comm: syz.0.1057 Tainted: G        W         syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:qdisc_match_from_root net/sched/sch_api.c:266 [inline]
RIP: 0010:qdisc_lookup+0x2da/0x4e0 net/sched/sch_api.c:309
Code: 74 6c 4d 8d 7e 10 4c 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 be 01 00 00 45 8b 3f 44 89 fe 83 e6 01 31 ff e8 86 42 b2 fd <41> 83 e7 01 75 77 4d 8d 7e 38 4c 89 f8 48 c1 e8 03 42 0f b6 04 28
RSP: 0018:ffffc90000b46ec8 EFLAGS: 00000297
RAX: ffffffff83b2777a RBX: 00000000ffff0000 RCX: 0000000000000002
RDX: ffff88810ecf0000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000b46ef8 R08: ffff88810ecf0000 R09: 0000000000000002
R10: 00000000ffffffff R11: 0000000000000002 R12: ffff888126386000
R13: dffffc0000000000 R14: ffff888113956800 R15: 0000000000000022
FS:  00007fc07eb446c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000002f48 CR3: 0000000126872000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 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: 0033:0x7fc08010a629
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:00007fc07eb44028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fc080384090 RCX: 00007fc08010a629
RDX: 0000000000008840 RSI: 0000200000000740 RDI: 0000000000000008
RBP: 00007fc0801a0b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc080384128 R14: 00007fc080384090 R15: 00007fff87993fc8
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:60 [inline]
NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:103 [inline]
NMI backtrace for cpu 0 skipped: idling at default_idle+0x12/0x20 arch/x86/kernel/process.c:717