skbuff: skb_under_panic: text:000000008bc13398 len:30 put:24 head:000000005d8f830a data:00000000c4a68d4b tail:0x6 end:0xc0 dev:gre0 ------------[ cut here ]------------ kernel BUG at net/core/skbuff.c:104! invalid opcode: 0000 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 1 PID: 29897 Comm: syz-executor5 Not tainted 4.15.0-rc8+ #205 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:skb_panic+0x162/0x1f0 net/core/skbuff.c:100 RSP: 0018:ffff8801aa68f9f8 EFLAGS: 00010282 RAX: 0000000000000083 RBX: ffff8801a7d01840 RCX: 0000000000000000 RDX: 0000000000000083 RSI: ffffc90001d89000 RDI: ffffed00354d1f33 RBP: ffff8801aa68fa60 R08: 1ffff100354d1ec1 R09: 0000000000000000 R10: ffff8801aa68f8a0 R11: 0000000000000000 R12: ffffffff861fb220 R13: ffffffff84a5f0ad R14: 0000000000000018 R15: ffff8801d006ed40 FS: 00007efd1d761700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000207f6ff4 CR3: 00000001bded0004 CR4: 00000000001606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: skb_under_panic net/core/skbuff.c:114 [inline] skb_push+0xce/0xf0 net/core/skbuff.c:1714 ipgre_header+0x6d/0x4e0 net/ipv4/ip_gre.c:879 dev_hard_header include/linux/netdevice.h:2731 [inline] pppoe_sendmsg+0x58e/0x8b0 drivers/net/ppp/pppoe.c:890 sock_sendmsg_nosec net/socket.c:630 [inline] sock_sendmsg+0xca/0x110 net/socket.c:640 sock_write_iter+0x31a/0x5d0 net/socket.c:909 call_write_iter include/linux/fs.h:1772 [inline] new_sync_write fs/read_write.c:469 [inline] __vfs_write+0x684/0x970 fs/read_write.c:482 vfs_write+0x189/0x510 fs/read_write.c:544 SYSC_write fs/read_write.c:589 [inline] SyS_write+0xef/0x220 fs/read_write.c:581 entry_SYSCALL_64_fastpath+0x29/0xa0 RIP: 0033:0x452f19 RSP: 002b:00007efd1d760c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000452f19 RDX: 0000000000000000 RSI: 000000002000fffe RDI: 0000000000000013 RBP: 00000000000001b0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f1920 R13: 00000000ffffffff R14: 00007efd1d7616d4 R15: 0000000000000000 Code: 04 01 84 c0 74 04 3c 03 7e 23 8b 8b 80 00 00 00 41 57 48 c7 c7 e0 aa 1f 86 52 56 4c 89 ea 41 50 4c 89 e6 45 89 f0 e8 66 e2 26 fd <0f> 0b 4c 89 4d b8 4c 89 45 c0 48 89 75 c8 48 89 55 d0 e8 87 3a RIP: skb_panic+0x162/0x1f0 net/core/skbuff.c:100 RSP: ffff8801aa68f9f8 ---[ end trace 8845d0bc890604eb ]--- Kernel panic - not syncing: Fatal exception Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled Rebooting in 86400 seconds..