skbuff: skb_under_panic: text:000000005b14eba7 len:31 put:24 head:0000000002b4e708 data:000000003ddf597d tail:0x7 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: 0 PID: 30250 Comm: syz-executor7 Not tainted 4.15.0-rc8+ #264 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:ffff8801d904f840 EFLAGS: 00010282 RAX: 0000000000000083 RBX: ffff8801d992c0c0 RCX: 0000000000000000 RDX: 0000000000000083 RSI: ffffc90003fe5000 RDI: ffffed003b209efc RBP: ffff8801d904f8a8 R08: 1ffff1003b209e8a R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff861f9020 R13: ffffffff84a31e3d R14: 0000000000000018 R15: ffff8801d4dda940 FS: 00007f39642b2700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000071c000 CR3: 00000001bad0b006 CR4: 00000000001606f0 DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 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:877 dev_hard_header include/linux/netdevice.h:2721 [inline] pppoe_sendmsg+0x58e/0x8b0 drivers/net/ppp/pppoe.c:890 sock_sendmsg_nosec net/socket.c:638 [inline] sock_sendmsg+0xca/0x110 net/socket.c:648 sock_write_iter+0x31a/0x5d0 net/socket.c:917 call_write_iter include/linux/fs.h:1772 [inline] do_iter_readv_writev+0x525/0x7f0 fs/read_write.c:653 do_iter_write+0x154/0x540 fs/read_write.c:932 vfs_writev+0x18a/0x340 fs/read_write.c:977 do_writev+0xfc/0x2a0 fs/read_write.c:1012 SYSC_writev fs/read_write.c:1085 [inline] SyS_writev+0x27/0x30 fs/read_write.c:1082 entry_SYSCALL_64_fastpath+0x29/0xa0 RIP: 0033:0x452df9 RSP: 002b:00007f39642b1c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000452df9 RDX: 0000000000000001 RSI: 0000000020211f90 RDI: 0000000000000013 RBP: 00000000000005b5 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f6998 R13: 00000000ffffffff R14: 00007f39642b26d4 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 88 1f 86 52 56 4c 89 ea 41 50 4c 89 e6 45 89 f0 e8 b6 bd 28 fd <0f> 0b 4c 89 4d b8 4c 89 45 c0 48 89 75 c8 48 89 55 d0 e8 c7 0a RIP: skb_panic+0x162/0x1f0 net/core/skbuff.c:100 RSP: ffff8801d904f840 ---[ end trace fcdebda091d58ed7 ]---