watchdog: BUG: soft lockup - CPU#1 stuck for 123s! [syz.3.46:480]
Modules linked in:
CPU: 1 PID: 480 Comm: syz.3.46 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:__qdisc_qstats_drop include/net/sch_generic.h:927 [inline]
RIP: 0010:qdisc_tree_reduce_backlog+0x249/0x340 net/sched/sch_api.c:798
Code: f8 48 c1 e8 03 42 0f b6 04 30 84 c0 0f 85 9f 00 00 00 8b 45 c4 41 29 87 c8 00 00 00 49 81 c5 cc 00 00 00 4c 89 e8 48 c1 e8 03 <42> 0f b6 04 30 84 c0 0f 85 94 00 00 00 8b 45 cc 41 01 45 00 e9 d8
RSP: 0018:ffffc90000ee6f28 EFLAGS: 00000a07
RAX: 1ffff11022625399 RBX: dffffc0000000000 RCX: ffff8881139d62c0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888113129cc8
RBP: ffffc90000ee6f70 R08: ffff8881139d62c0 R09: 0000000000000002
R10: 00000000ffffffff R11: 0000000000000000 R12: 00000000fffffff1
R13: ffff888113129ccc R14: dffffc0000000000 R15: ffff888113129c00
FS:  00007f57384e96c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f68853add58 CR3: 00000001322a0000 CR4: 00000000003526a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000085
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 fq_change+0xbdb/0x1100 net/sched/sch_fq.c:915
 fq_init+0x3e3/0x5d0 net/sched/sch_fq.c:963
 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:5613
 netlink_rcv_skb+0x1f5/0x440 net/netlink/af_netlink.c:2503
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5631
 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: 0033:0x7f5739a8edd9
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:00007f57384e9028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f5739d07fa0 RCX: 00007f5739a8edd9
RDX: 0000000000000000 RSI: 0000200000001200 RDI: 0000000000000003
RBP: 00007f5739b24d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5739d08038 R14: 00007f5739d07fa0 R15: 00007ffd71cdd218
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