stack segment: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 5332 Comm: syz.2.248 Not tainted 5.15.187-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:qdisc_tree_reduce_backlog+0x1f9/0x430 net/sched/sch_api.c:794
Code: 80 3c 28 00 74 08 48 89 df e8 13 2a c8 f9 4d 89 e6 85 ed 74 07 e8 07 b1 82 f9 eb 7b 48 8b 1b 48 8d 43 20 48 89 c5 48 c1 ed 03 <42> 80 7c 2d 00 00 48 89 04 24 74 0d 48 8b 3c 24 e8 e2 29 c8 f9 48
RSP: 0018:ffffc9000393ef70 EFLAGS: 00010202
RAX: 0000000000000020 RBX: 0000000000000000 RCX: ffff888025efbb80
RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000004 R08: ffff888025efbb80 R09: 0000000000000002
R10: 00000000ffffffff R11: 0000000000000002 R12: ffff888077561000
R13: dffffc0000000000 R14: ffff888077561000 R15: 00000000000bffe6
FS:  00007fe0d7e126c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbb1e9af2d8 CR3: 000000005ae5a000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 codel_change+0x8d1/0xc00 net/sched/sch_codel.c:183
 codel_init+0x190/0x330 net/sched/sch_codel.c:202
 qdisc_create+0x7bd/0x1170 net/sched/sch_api.c:1260
 tc_modify_qdisc+0xaad/0x16c0 net/sched/sch_api.c:-1
 rtnetlink_rcv_msg+0x9b9/0xe60 net/core/rtnetlink.c:5650
 netlink_rcv_skb+0x1e0/0x430 net/netlink/af_netlink.c:2489
 netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline]
 netlink_unicast+0x77c/0x920 net/netlink/af_netlink.c:1337
 netlink_sendmsg+0x8ab/0xbc0 net/netlink/af_netlink.c:1905
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 ____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2436
 ___sys_sendmsg+0x1f0/0x260 net/socket.c:2490
 __sys_sendmsg net/socket.c:2519 [inline]
 __do_sys_sendmsg net/socket.c:2528 [inline]
 __se_sys_sendmsg+0x190/0x250 net/socket.c:2526
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fe0d9fec929
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe0d7e12038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fe0da214160 RCX: 00007fe0d9fec929
RDX: 0000000004008000 RSI: 0000200000000200 RDI: 0000000000000005
RBP: 00007fe0da06eb39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007fe0da214160 R15: 00007ffcf65208c8
 </TASK>
Modules linked in:
---[ end trace bbe66061f9da2a44 ]---
RIP: 0010:qdisc_tree_reduce_backlog+0x1f9/0x430 net/sched/sch_api.c:794
Code: 80 3c 28 00 74 08 48 89 df e8 13 2a c8 f9 4d 89 e6 85 ed 74 07 e8 07 b1 82 f9 eb 7b 48 8b 1b 48 8d 43 20 48 89 c5 48 c1 ed 03 <42> 80 7c 2d 00 00 48 89 04 24 74 0d 48 8b 3c 24 e8 e2 29 c8 f9 48
RSP: 0018:ffffc9000393ef70 EFLAGS: 00010202
RAX: 0000000000000020 RBX: 0000000000000000 RCX: ffff888025efbb80
RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000004 R08: ffff888025efbb80 R09: 0000000000000002
R10: 00000000ffffffff R11: 0000000000000002 R12: ffff888077561000
R13: dffffc0000000000 R14: ffff888077561000 R15: 00000000000bffe6
FS:  00007fe0d7e126c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbb1e9af2d8 CR3: 000000005ae5a000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	80 3c 28 00          	cmpb   $0x0,(%rax,%rbp,1)
   4:	74 08                	je     0xe
   6:	48 89 df             	mov    %rbx,%rdi
   9:	e8 13 2a c8 f9       	call   0xf9c82a21
   e:	4d 89 e6             	mov    %r12,%r14
  11:	85 ed                	test   %ebp,%ebp
  13:	74 07                	je     0x1c
  15:	e8 07 b1 82 f9       	call   0xf982b121
  1a:	eb 7b                	jmp    0x97
  1c:	48 8b 1b             	mov    (%rbx),%rbx
  1f:	48 8d 43 20          	lea    0x20(%rbx),%rax
  23:	48 89 c5             	mov    %rax,%rbp
  26:	48 c1 ed 03          	shr    $0x3,%rbp
* 2a:	42 80 7c 2d 00 00    	cmpb   $0x0,0x0(%rbp,%r13,1) <-- trapping instruction
  30:	48 89 04 24          	mov    %rax,(%rsp)
  34:	74 0d                	je     0x43
  36:	48 8b 3c 24          	mov    (%rsp),%rdi
  3a:	e8 e2 29 c8 f9       	call   0xf9c82a21
  3f:	48                   	rex.W