watchdog: BUG: soft lockup - CPU#1 stuck for 225s! [syz.1.907:3700]
Modules linked in:
CPU: 1 PID: 3700 Comm: syz.1.907 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__sanitizer_cov_trace_pc+0x45/0x60 kernel/kcov.c:211
Code: ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 5c 0b 00 00 00 74 2c 8b 91 38 0b 00 00 83 fa 02 75 21 48 8b 91 40 0b 00 00 48 8b 32 <48> 8d 7e 01 8b 89 3c 0b 00 00 48 39 cf 73 08 48 89 44 f2 08 48 89
RSP: 0018:ffffc90001206e78 EFLAGS: 00000246
RAX: ffffffff83d22735 RBX: 00000000ffff0000 RCX: ffff888113244f00
RDX: ffffc900013ab000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90001206e78 R08: ffff888113244f00 R09: 0000000000000002
R10: 00000000ffffffff R11: 0000000000000002 R12: 0000000000000000
R13: dffffc0000000000 R14: ffffffffffffffd8 R15: ffff88812111c000
FS:  00007fc717fae6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000000 CR3: 000000010d69b000 CR4: 00000000003506a0
DR0: 0000000000009000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 qdisc_match_from_root net/sched/sch_api.c:270 [inline]
 qdisc_lookup+0x1a5/0x4e0 net/sched/sch_api.c:304
 qdisc_tree_reduce_backlog+0x111/0x340 net/sched/sch_api.c:794
 fq_codel_change+0xa71/0xf10 net/sched/sch_fq_codel.c:438
 fq_codel_init+0x342/0xa20 net/sched/sch_fq_codel.c:475
 qdisc_create+0x7ed/0x11a0 net/sched/sch_api.c:1266
 tc_modify_qdisc+0x8eb/0x15a0 net/sched/sch_api.c:1726
 rtnetlink_rcv_msg+0x9e4/0xb90 net/core/rtnetlink.c:5650
 netlink_rcv_skb+0x1e0/0x430 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+0x86a/0xb70 net/netlink/af_netlink.c:1922
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 ____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2436
 ___sys_sendmsg+0x1f0/0x260 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+0x1e2/0x2a0 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: 0033:0x7fc719545be9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc717fae038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fc71977cfa0 RCX: 00007fc719545be9
RDX: 0000000000044080 RSI: 0000200000000140 RDI: 0000000000000009
RBP: 00007fc7195c8e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc71977d038 R14: 00007fc71977cfa0 R15: 00007ffe671902c8
 </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:728