syzbot

IPVS: ftp: loaded support on port[0] = 21
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 9829 Comm: syz-executor938 Not tainted 5.3.0-rc8+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__list_del_entry_valid+0x85/0xf5 lib/list_debug.c:51
Code: 0f 84 e1 00 00 00 48 b8 22 01 00 00 00 00 ad de 49 39 c4 0f 84 e2 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 75 53 49 8b 14 24 4c 39 f2 0f 85 99 00 00 00 49 8d 7d
RSP: 0018:ffff88809689f450 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffff8880921f9680 RCX: ffffffff8159c28a
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8880921f99e8
RBP: ffff88809689f468 R08: 0000000000000004 R09: ffffed1012d13e7d
R10: ffffed1012d13e7c R11: 0000000000000003 R12: 0000000000000000
R13: 0000000000000000 R14: ffff8880921f99e0 R15: ffff8880921f9940
FS:  0000555556e2b880(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000200001c0 CR3: 00000000a1971000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __list_del_entry include/linux/list.h:131 [inline]
 list_del include/linux/list.h:139 [inline]
 cbs_destroy+0x7d/0x2a0 net/sched/sch_cbs.c:435
 qdisc_create+0xbc6/0x1210 net/sched/sch_api.c:1285
 tc_modify_qdisc+0x524/0x1c50 net/sched/sch_api.c:1652
 rtnetlink_rcv_msg+0x463/0xb00 net/core/rtnetlink.c:5223
 netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477
 rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5241
 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
 netlink_unicast+0x531/0x710 net/netlink/af_netlink.c:1328
 netlink_sendmsg+0x8a5/0xd60 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg+0xd7/0x130 net/socket.c:657
 ___sys_sendmsg+0x803/0x920 net/socket.c:2311
 __sys_sendmsg+0x105/0x1d0 net/socket.c:2356
 __do_sys_sendmsg net/socket.c:2365 [inline]
 __se_sys_sendmsg net/socket.c:2363 [inline]
 __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2363
 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x440c69
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 0f 83 7b 10 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffd9e3e6f88 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004a23f0 RCX: 0000000000440c69
RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000000000003
RBP: 00000000006cb018 R08: 0000000120080522 R09: 0000000120080522
R10: 0000000120080522 R11: 0000000000000246 R12: 0000000000402170
R13: 0000000000402200 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
---[ end trace 58f5f8ce23e586ff ]---
RIP: 0010:__list_del_entry_valid+0x85/0xf5 lib/list_debug.c:51
Code: 0f 84 e1 00 00 00 48 b8 22 01 00 00 00 00 ad de 49 39 c4 0f 84 e2 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 75 53 49 8b 14 24 4c 39 f2 0f 85 99 00 00 00 49 8d 7d
RSP: 0018:ffff88809689f450 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffff8880921f9680 RCX: ffffffff8159c28a
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8880921f99e8
RBP: ffff88809689f468 R08: 0000000000000004 R09: ffffed1012d13e7d
R10: ffffed1012d13e7c R11: 0000000000000003 R12: 0000000000000000
R13: 0000000000000000 R14: ffff8880921f99e0 R15: ffff8880921f9940
FS:  0000555556e2b880(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000200001c0 CR3: 00000000a1971000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400