Oops: general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027]
CPU: 1 UID: 0 PID: 7989 Comm: syz.4.547 Not tainted 6.16.0-rc5-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:qdisc_tree_reduce_backlog+0x223/0x480 net/sched/sch_api.c:806
Code: 89 ef e8 40 04 ab f8 4d 89 ef 85 db 74 0d e8 84 81 47 f8 4c 89 f5 e9 88 00 00 00 48 8b 6d 00 48 8d 45 20 48 89 c3 48 c1 eb 03 <42> 80 3c 33 00 48 89 04 24 74 0d 48 8b 3c 24 e8 09 04 ab f8 48 8b
RSP: 0018:ffffc9000400f128 EFLAGS: 00010202
RAX: 0000000000000020 RBX: 0000000000000004 RCX: 0000000000000002
RDX: ffff8880253f1e00 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffff8880253f1e00 R09: 0000000000000002
R10: 00000000ffffffff R11: 0000000000000002 R12: 00000000000b0002
R13: ffff8880320b9800 R14: dffffc0000000000 R15: ffff8880320b9800
FS:  0000000000000000(0000) GS:ffff888125d1d000(0063) knlGS:00000000f5035b40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000080000040 CR3: 0000000077b60000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 hhf_change+0x764/0xad0 net/sched/sch_hhf.c:571
 hhf_init+0x213/0x950 net/sched/sch_hhf.c:597
 qdisc_create+0x7ac/0xea0 net/sched/sch_api.c:1324
 __tc_modify_qdisc net/sched/sch_api.c:1749 [inline]
 tc_modify_qdisc+0x1426/0x2010 net/sched/sch_api.c:1813
 rtnetlink_rcv_msg+0x779/0xb70 net/core/rtnetlink.c:6953
 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2534
 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
 netlink_unicast+0x75b/0x8d0 net/netlink/af_netlink.c:1339
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:727
 ____sys_sendmsg+0x505/0x830 net/socket.c:2566
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2620
 __sys_sendmsg+0x164/0x220 net/socket.c:2652
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xb6/0x2b0 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7f32539
Code: 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f503555c EFLAGS: 00000206 ORIG_RAX: 0000000000000172
RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 0000000080000200
RDX: 0000000004008000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:qdisc_tree_reduce_backlog+0x223/0x480 net/sched/sch_api.c:806
Code: 89 ef e8 40 04 ab f8 4d 89 ef 85 db 74 0d e8 84 81 47 f8 4c 89 f5 e9 88 00 00 00 48 8b 6d 00 48 8d 45 20 48 89 c3 48 c1 eb 03 <42> 80 3c 33 00 48 89 04 24 74 0d 48 8b 3c 24 e8 09 04 ab f8 48 8b
RSP: 0018:ffffc9000400f128 EFLAGS: 00010202
RAX: 0000000000000020 RBX: 0000000000000004 RCX: 0000000000000002
RDX: ffff8880253f1e00 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffff8880253f1e00 R09: 0000000000000002
R10: 00000000ffffffff R11: 0000000000000002 R12: 00000000000b0002
R13: ffff8880320b9800 R14: dffffc0000000000 R15: ffff8880320b9800
FS:  0000000000000000(0000) GS:ffff888125d1d000(0063) knlGS:00000000f5035b40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000080000040 CR3: 0000000077b60000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	89 ef                	mov    %ebp,%edi
   2:	e8 40 04 ab f8       	call   0xf8ab0447
   7:	4d 89 ef             	mov    %r13,%r15
   a:	85 db                	test   %ebx,%ebx
   c:	74 0d                	je     0x1b
   e:	e8 84 81 47 f8       	call   0xf8478197
  13:	4c 89 f5             	mov    %r14,%rbp
  16:	e9 88 00 00 00       	jmp    0xa3
  1b:	48 8b 6d 00          	mov    0x0(%rbp),%rbp
  1f:	48 8d 45 20          	lea    0x20(%rbp),%rax
  23:	48 89 c3             	mov    %rax,%rbx
  26:	48 c1 eb 03          	shr    $0x3,%rbx
* 2a:	42 80 3c 33 00       	cmpb   $0x0,(%rbx,%r14,1) <-- trapping instruction
  2f:	48 89 04 24          	mov    %rax,(%rsp)
  33:	74 0d                	je     0x42
  35:	48 8b 3c 24          	mov    (%rsp),%rdi
  39:	e8 09 04 ab f8       	call   0xf8ab0447
  3e:	48                   	rex.W
  3f:	8b                   	.byte 0x8b