watchdog: BUG: soft lockup - CPU#1 stuck for 115s! [syz.4.5875:23145]
Modules linked in:
CPU: 1 PID: 23145 Comm: syz.4.5875 Tainted: G        W         syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:check_kcov_mode kernel/kcov.c:174 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x36/0x60 kernel/kcov.c:197
Code: 30 c9 9e 7e 65 8b 15 35 c9 9e 7e f7 c2 00 01 ff 00 74 11 f7 c2 00 01 00 00 74 35 83 b9 dc 0a 00 00 00 74 2c 8b 91 b8 0a 00 00 <83> fa 02 75 21 48 8b 91 c0 0a 00 00 48 8b 32 48 8d 7e 01 8b 89 bc
RSP: 0018:ffffc9000134eeb8 EFLAGS: 00000246
RAX: ffffffff83ab1465 RBX: 00000000ffff0000 RCX: ffff888110ae13c0
RDX: 0000000000000002 RSI: 00000000ffff0000 RDI: 00000000000a0000
RBP: ffffc9000134eeb8 R08: ffff888110ae13c0 R09: 0000000000000002
R10: 00000000ffffffff R11: 0000000000000002 R12: 00000000000a0000
R13: dffffc0000000000 R14: ffff88813095a400 R15: ffff888128e16000
FS:  00007f5a57aa26c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000010000ff CR3: 0000000113ed7000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 qdisc_match_from_root net/sched/sch_api.c:266 [inline]
 qdisc_lookup+0x165/0x4e0 net/sched/sch_api.c:304
 qdisc_tree_reduce_backlog+0x111/0x340 net/sched/sch_api.c:793
 fq_codel_change+0xa27/0xe40 net/sched/sch_fq_codel.c:436
 fq_codel_init+0x342/0xa20 net/sched/sch_fq_codel.c:473
 qdisc_create+0x780/0x1040 net/sched/sch_api.c:1265
 tc_modify_qdisc+0x8da/0x14c0 net/sched/sch_api.c:1725
 rtnetlink_rcv_msg+0x9db/0xb90 net/core/rtnetlink.c:5610
 netlink_rcv_skb+0x1e0/0x430 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+0x88d/0xb30 net/netlink/af_netlink.c:1914
 sock_sendmsg_nosec net/socket.c:652 [inline]
 __sock_sendmsg net/socket.c:664 [inline]
 ____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2376
 ___sys_sendmsg+0x1f0/0x260 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+0x1e2/0x2a0 net/socket.c:2466
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f5a5903a749
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:00007f5a57aa2038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f5a59290fa0 RCX: 00007f5a5903a749
RDX: 0000000020004000 RSI: 0000200000000640 RDI: 000000000000000a
RBP: 00007f5a590bef91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5a59291038 R14: 00007f5a59290fa0 R15: 00007ffc984970d8
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