watchdog: BUG: soft lockup - CPU#0 stuck for 123s! [syz.7.377:2043]
Modules linked in:
CPU: 0 PID: 2043 Comm: syz.7.377 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:qdisc_tree_reduce_backlog+0x209/0x380 net/sched/sch_api.c:811
Code: fd 49 8d bc 24 a8 00 00 00 48 89 f8 48 c1 e8 03 4d 89 ee 42 0f b6 04 28 84 c0 0f 85 c1 00 00 00 8b 45 d0 41 29 87 a8 00 00 00 <49> 8d bc 24 c8 00 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0
RSP: 0018:ffffc90000b26f28 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 1ffffffff0ae0fd8 RCX: 0000000000080000
RDX: ffffc9000975c000 RSI: 000000000007ffff RDI: ffff8881223868a8
RBP: ffffc90000b26f70 R08: 1ffff110227f0002 R09: 1ffff110227f0012
R10: 1ffff110227f0001 R11: fffff52000164de0 R12: ffff888122386800
R13: dffffc0000000000 R14: dffffc0000000000 R15: ffff888122386800
FS:  00007f1d030536c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1d03051fa8 CR3: 00000001122b1000 CR4: 00000000003526b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 fq_codel_change+0xa6d/0xeb0 net/sched/sch_fq_codel.c:473
 fq_codel_init+0x33f/0xa40 net/sched/sch_fq_codel.c:510
 qdisc_create+0x84c/0x1220 net/sched/sch_api.c:1269
 tc_modify_qdisc+0x8c2/0x1470 net/sched/sch_api.c:-1
 rtnetlink_rcv_msg+0x9e9/0xca0 net/core/rtnetlink.c:5622
 netlink_rcv_skb+0x1e9/0x430 net/netlink/af_netlink.c:2508
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5640
 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
 netlink_unicast+0x86c/0xa30 net/netlink/af_netlink.c:1340
 netlink_sendmsg+0x949/0xb70 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:652 [inline]
 __sock_sendmsg net/socket.c:664 [inline]
 ____sys_sendmsg+0x5be/0x8f0 net/socket.c:2377
 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2431
 __sys_sendmsg net/socket.c:2460 [inline]
 __do_sys_sendmsg net/socket.c:2469 [inline]
 __se_sys_sendmsg net/socket.c:2467 [inline]
 __x64_sys_sendmsg+0x201/0x2d0 net/socket.c:2467
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f1d0463c159
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:00007f1d03053028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f1d048c4180 RCX: 00007f1d0463c159
RDX: 0000000000008840 RSI: 0000200000000740 RDI: 000000000000000b
RBP: 00007f1d046d3024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1d048c4218 R14: 00007f1d048c4180 R15: 00007ffe83dedbc8
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:60 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:103 [inline]
NMI backtrace for cpu 1 skipped: idling at default_idle+0x12/0x20 arch/x86/kernel/process.c:717