**                                                      **
**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **
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protocol 88a8 is buggy, dev gre0
------------[ cut here ]------------
kernel BUG at net/ipv4/ip_output.c:776!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 24269 Comm: syz-executor0 Not tainted 4.20.0-rc7+ #248
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:ip_do_fragment+0x2454/0x2ad0 net/ipv4/ip_output.c:776
Code: 8b 8d 70 fe ff ff e9 69 e8 ff ff 4c 89 ef e8 b3 79 35 fb e9 4b e9 ff ff 4c 89 f7 e8 a6 79 35 fb e9 c3 e5 ff ff e8 ac 71 f2 fa <0f> 0b 4c 89 e7 e8 92 79 35 fb e9 87 e8 ff ff 4c 89 f7 89 8d 70 fe
RSP: 0018:ffff8881a22167b8 EFLAGS: 00010212
RAX: 0000000000040000 RBX: ffff8881bd15dbc0 RCX: ffffc90005fea000
RDX: 0000000000008f6f RSI: ffffffff868be6f4 RDI: 0000000000000005
RBP: ffff8881a2216990 R08: ffff8881b2c52280 R09: ffffed1030739c0a
R10: ffffed1030739c0c R11: ffff8881839ce063 R12: ffff8881bd15dc84
R13: 00000000fffffff2 R14: ffff8881bd15dc90 R15: dffffc0000000000
FS:  00007feb0e89e700(0000) GS:ffff8881daf00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000010a1e80 CR3: 0000000190995000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 ip_fragment.constprop.50+0x179/0x240 net/ipv4/ip_output.c:549
 ip_finish_output+0x6b4/0xf90 net/ipv4/ip_output.c:315
 NF_HOOK_COND include/linux/netfilter.h:278 [inline]
 ip_output+0x21d/0x8d0 net/ipv4/ip_output.c:405
 dst_output include/net/dst.h:444 [inline]
 ip_local_out+0xc5/0x1b0 net/ipv4/ip_output.c:124
 iptunnel_xmit+0x5d0/0x9c0 net/ipv4/ip_tunnel_core.c:91
 ip_tunnel_xmit+0x15b8/0x3c04 net/ipv4/ip_tunnel.c:787
 __gre_xmit+0x5e1/0x980 net/ipv4/ip_gre.c:451
 ipgre_xmit+0x3e7/0xba0 net/ipv4/ip_gre.c:705
 __netdev_start_xmit include/linux/netdevice.h:4356 [inline]
 netdev_start_xmit include/linux/netdevice.h:4365 [inline]
 xmit_one net/core/dev.c:3257 [inline]
 dev_hard_start_xmit+0x295/0xc90 net/core/dev.c:3273
 __dev_queue_xmit+0x2f0d/0x3950 net/core/dev.c:3843
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3876
 __bpf_tx_skb net/core/filter.c:2017 [inline]
 __bpf_redirect_common net/core/filter.c:2055 [inline]
 __bpf_redirect+0x5cf/0xb20 net/core/filter.c:2062
 ____bpf_clone_redirect net/core/filter.c:2095 [inline]
 bpf_clone_redirect+0x2f6/0x490 net/core/filter.c:2067
 bpf_prog_19df9f14ecbbb556+0xb3a/0x1000
Modules linked in:
---[ end trace 7968354e50106419 ]---
RIP: 0010:ip_do_fragment+0x2454/0x2ad0 net/ipv4/ip_output.c:776
Code: 8b 8d 70 fe ff ff e9 69 e8 ff ff 4c 89 ef e8 b3 79 35 fb e9 4b e9 ff ff 4c 89 f7 e8 a6 79 35 fb e9 c3 e5 ff ff e8 ac 71 f2 fa <0f> 0b 4c 89 e7 e8 92 79 35 fb e9 87 e8 ff ff 4c 89 f7 89 8d 70 fe
RSP: 0018:ffff8881a22167b8 EFLAGS: 00010212
RAX: 0000000000040000 RBX: ffff8881bd15dbc0 RCX: ffffc90005fea000
RDX: 0000000000008f6f RSI: ffffffff868be6f4 RDI: 0000000000000005
RBP: ffff8881a2216990 R08: ffff8881b2c52280 R09: ffffed1030739c0a
R10: ffffed1030739c0c R11: ffff8881839ce063 R12: ffff8881bd15dc84
R13: 00000000fffffff2 R14: ffff8881bd15dc90 R15: dffffc0000000000
FS:  00007feb0e89e700(0000) GS:ffff8881daf00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000010a1e80 CR3: 0000000190995000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400