protocol 2cea is buggy, dev gre0 protocol 2cea is buggy, dev gre0 ------------[ cut here ]------------ kernel BUG at net/ipv4/ip_output.c:776! invalid opcode: 0000 [#1] PREEMPT SMP KASAN ------------[ cut here ]------------ CPU: 0 PID: 4099 Comm: syz-executor3 Not tainted 4.20.0-rc6+ #108 downgrading a read lock WARNING: CPU: 1 PID: 4134 at kernel/locking/lockdep.c:3556 __lock_downgrade kernel/locking/lockdep.c:3556 [inline] WARNING: CPU: 1 PID: 4134 at kernel/locking/lockdep.c:3556 lock_downgrade+0x4d7/0x900 kernel/locking/lockdep.c:3819 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Kernel panic - not syncing: panic_on_warn set ... RIP: 0010:ip_do_fragment+0x2447/0x2ad0 net/ipv4/ip_output.c:776 Code: ff 48 89 cf e8 1a 4c 33 fb e9 dc ea ff ff 48 89 df e8 4d 4c 33 fb e9 02 e7 ff ff e8 a3 4c 33 fb e9 97 e6 ff ff e8 59 e6 ef fa <0f> 0b 4c 89 f7 e8 ef 4b 33 fb e9 2f e6 ff ff 4c 89 e7 e8 e2 4b 33 RSP: 0018:ffff88806bc6e778 EFLAGS: 00010246 RAX: 0000000000040000 RBX: ffff88809a8f6e80 RCX: ffffc9000be41000 RDX: 0000000000040000 RSI: ffffffff868f3037 RDI: 0000000000000005 RBP: ffff88806bc6e950 R08: ffff888085fa82c0 R09: ffffed100c831e4a R10: ffffed100c831e4c R11: ffff88806418f263 R12: ffff88809a8f6f44 R13: 00000000fffffff2 R14: ffff88809a8f6f50 R15: dffffc0000000000 FS: 00007f3495b41700(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007eff4a1cb000 CR3: 0000000092b7b000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: ip_fragment.constprop.50+0x179/0x240 net/ipv4/ip_output.c:549 ip_finish_output+0x6b4/0xfa0 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+0x63b/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+0x295/0xc80 net/core/dev.c:3273 __dev_queue_xmit+0x2f71/0x3ad0 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_bebbfe2050753572+0x6c5/0x1000 Modules linked in: Kernel Offset: disabled Rebooting in 86400 seconds..