------------[ cut here ]------------
WARNING: CPU: 1 PID: 18888 at net/sched/sch_taprio.c:999 __refcount_sub_and_test include/linux/refcount.h:283 [inline]
WARNING: CPU: 1 PID: 18888 at net/sched/sch_taprio.c:999 __refcount_dec_and_test include/linux/refcount.h:315 [inline]
WARNING: CPU: 1 PID: 18888 at net/sched/sch_taprio.c:999 refcount_dec_and_test include/linux/refcount.h:333 [inline]
WARNING: CPU: 1 PID: 18888 at net/sched/sch_taprio.c:999 taprio_offload_free net/sched/sch_taprio.c:1151 [inline]
WARNING: CPU: 1 PID: 18888 at net/sched/sch_taprio.c:999 taprio_enable_offload net/sched/sch_taprio.c:1261 [inline]
WARNING: CPU: 1 PID: 18888 at net/sched/sch_taprio.c:999 taprio_change+0x5005/0x5b60 net/sched/sch_taprio.c:1513
Modules linked in:
CPU: 1 PID: 18888 Comm: syz-executor.1 Not tainted 5.12.0-rc8-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:taprio_get_start_time include/linux/refcount.h:283 [inline]
RIP: 0010:taprio_change+0x5005/0x5b60 net/sched/sch_taprio.c:1550
Code: ff 48 89 df e8 fc ec c0 f9 e9 8a b7 ff ff e8 92 6c 7a f9 48 8b bc 24 b0 00 00 00 be 03 00 00 00 e8 70 c8 f1 fb e9 74 f3 ff ff <0f> 0b 48 c7 c7 a0 6e 35 8b e8 8d 08 07 00 48 83 7c 24 08 00 0f 84
RSP: 0018:ffffc9001702ee00 EFLAGS: 00010246
RAX: 0000000000000002 RBX: 0000000000000000 RCX: 1ffff110023f5e06
RDX: ffff88801aa23880 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9001702f110 R08: ffffffff880415dc R09: fffffbfff1f992cc
R10: fffffbfff1f992cc R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000000 R14: 00000058c03a8537 R15: ffff8880199b1800
FS:  00007f4a35b6b700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000051e3b0 CR3: 0000000024957000 CR4: 00000000001526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 qdisc_create+0x83a/0x1620 net/sched/sch_api.c:1247
 tc_modify_qdisc+0x9ef/0x2060 net/sched/sch_api.c:1663
 rtnetlink_rcv_msg+0xb34/0xe70 net/core/rtnetlink.c:5553
 netlink_rcv_skb+0x1f0/0x460 net/netlink/af_netlink.c:2502
 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline]
 netlink_unicast+0x7de/0x9b0 net/netlink/af_netlink.c:1338
 netlink_sendmsg+0xaa6/0xe90 net/netlink/af_netlink.c:1927
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg net/socket.c:674 [inline]
 ____sys_sendmsg+0x5a2/0x900 net/socket.c:2350
 ___sys_sendmsg net/socket.c:2404 [inline]
 __sys_sendmsg+0x319/0x400 net/socket.c:2433
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665f9
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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f4a35b6b188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 00000000004665f9
RDX: 0000000000000000 RSI: 00000000200007c0 RDI: 0000000000000004
RBP: 00000000004bfbb9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60
R13: 00007fff5af5ceaf R14: 00007f4a35b6b300 R15: 0000000000022000