BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 12a5a067 P4D 12a5a067 PUD 2a5a0067 PMD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 12857 Comm: syz-executor.5 Not tainted 5.11.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
RSP: 0018:ffffc90002e47508 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: 1ffff920005c8ea3 RCX: 0000000000000000
RDX: ffffc90002e47548 RSI: 0000000000000012 RDI: ffff888012b52000
RBP: ffff888012b52000 R08: ffff888019c30c18 R09: 0000000000000000
R10: ffffffff8979d8e8 R11: fffff520005c8ea1 R12: ffffffff890469c0
R13: 00000000ffff0000 R14: ffff888019c30c1c R15: ffff888019e7a000
FS:  00007f5bf96f2700(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000000143db000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 htb_offload net/sched/sch_htb.c:1010 [inline]
 htb_select_queue+0x174/0x290 net/sched/sch_htb.c:1303
 tc_modify_qdisc+0x35d/0x1630 net/sched/sch_api.c:1657
 rtnetlink_rcv_msg+0x32f/0x860 net/core/rtnetlink.c:5553
 netlink_rcv_skb+0x118/0x370 net/netlink/af_netlink.c:2494
 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
 netlink_unicast+0x42e/0x700 net/netlink/af_netlink.c:1330
 netlink_sendmsg+0x70e/0xbe0 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xab/0xe0 net/socket.c:672
 ____sys_sendmsg+0x5bf/0x7a0 net/socket.c:2345
 ___sys_sendmsg+0xd3/0x150 net/socket.c:2399
 __sys_sendmsg+0xb2/0x140 net/socket.c:2432
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x466019
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:00007f5bf96f2188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466019
RDX: 0000000000000000 RSI: 00000000200007c0 RDI: 0000000000000004
RBP: 00000000004bd067 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60
R13: 00007ffccab5a9ef R14: 00007f5bf96f2300 R15: 0000000000022000
Modules linked in:
CR2: 0000000000000000
---[ end trace 59fc7d769346345d ]---
RIP: 0010:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
RSP: 0018:ffffc90002e47508 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: 1ffff920005c8ea3 RCX: 0000000000000000
RDX: ffffc90002e47548 RSI: 0000000000000012 RDI: ffff888012b52000
RBP: ffff888012b52000 R08: ffff888019c30c18 R09: 0000000000000000
R10: ffffffff8979d8e8 R11: fffff520005c8ea1 R12: ffffffff890469c0
R13: 00000000ffff0000 R14: ffff888019c30c1c R15: ffff888019e7a000
FS:  00007f5bf96f2700(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff85574850 CR3: 00000000143db000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400