list_del corruption, ffff88019864a328->next is LIST_POISON1 (dead000000000100)
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:47!
invalid opcode: 0000 [#1] SMP KASAN
CPU: 1 PID: 11666 Comm: syz-executor783 Not tainted 4.18.0-rc4-next-20180711+ #4
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__list_del_entry_valid.cold.1+0x26/0x58 lib/list_debug.c:45
Code: ff fd 0f 0b 4c 89 e2 48 89 de 48 c7 c7 e0 8c 1a 88 e8 3a 00 ff fd 0f 0b 4c 89 ea 48 89 de 48 c7 c7 80 8c 1a 88 e8 26 00 ff fd <0f> 0b 48 89 de 48 c7 c7 a0 8d 1a 88 e8 15 00 ff fd 0f 0b 48 89 de 
RSP: 0018:ffff880198647270 EFLAGS: 00010286
RAX: 000000000000004e RBX: ffff88019864a328 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff81634131 RDI: 0000000000000001
RBP: ffff880198647288 R08: ffff8801b3f82740 R09: ffffed003b5e4fc0
R10: ffffed003b5e4fc0 R11: ffff8801daf27e07 R12: dead000000000200
R13: dead000000000100 R14: ffff88019864a328 R15: ffff88019864a330
FS:  00007fd6c8c6f700(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffcb755620 CR3: 00000001b82f0000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __list_del_entry include/linux/list.h:117 [inline]
 list_del include/linux/list.h:125 [inline]
 p9_fd_cancel+0x104/0x360 net/9p/trans_fd.c:690
 p9_client_rpc+0xf1f/0x1400 net/9p/client.c:801
 p9_client_version net/9p/client.c:977 [inline]
 p9_client_create+0xdb0/0x1770 net/9p/client.c:1070
9pnet: Insufficient options for proto=fd
 v9fs_session_init+0x21a/0x1a80 fs/9p/v9fs.c:400
 v9fs_mount+0x7c/0x900 fs/9p/vfs_super.c:135
 legacy_get_tree+0x118/0x440 fs/fs_context.c:659
 vfs_get_tree+0x1cb/0x5c0 fs/super.c:1743
 do_new_mount fs/namespace.c:2567 [inline]
 do_mount+0x6c1/0x1fb0 fs/namespace.c:2889
 ksys_mount+0x12d/0x140 fs/namespace.c:3105
 __do_sys_mount fs/namespace.c:3119 [inline]
 __se_sys_mount fs/namespace.c:3116 [inline]
 __x64_sys_mount+0xbe/0x150 fs/namespace.c:3116
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x446229
Code: e8 ac e7 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 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 fb 0d fc ff c3 66 2e 0f 1f 84 00 00 00 00 
RSP: 002b:00007fd6c8c6eda8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00000000006dbc64 RCX: 0000000000446229
RDX: 0000000020000380 RSI: 0000000020000000 RDI: 0000000000000000
RBP: 00000000006dbc60 R08: 0000000020000240 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0030656c69662f2e
R13: 64663d736e617274 R14: 613d737365636361 R15: 0000000000002710
Modules linked in:
Dumping ftrace buffer:
   (ftrace buffer empty)
---[ end trace 273fa82386a499f8 ]---
RIP: 0010:__list_del_entry_valid.cold.1+0x26/0x58 lib/list_debug.c:45
Code: ff fd 0f 0b 4c 89 e2 48 89 de 48 c7 c7 e0 8c 1a 88 e8 3a 00 ff fd 0f 0b 4c 89 ea 48 89 de 48 c7 c7 80 8c 1a 88 e8 26 00 ff fd <0f> 0b 48 89 de 48 c7 c7 a0 8d 1a 88 e8 15 00 ff fd 0f 0b 48 89 de 
RSP: 0018:ffff880198647270 EFLAGS: 00010286
RAX: 000000000000004e RBX: ffff88019864a328 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff81634131 RDI: 0000000000000001
RBP: ffff880198647288 R08: ffff8801b3f82740 R09: ffffed003b5e4fc0
R10: ffffed003b5e4fc0 R11: ffff8801daf27e07 R12: dead000000000200
R13: dead000000000100 R14: ffff88019864a328 R15: ffff88019864a330
FS:  00007fd6c8c6f700(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffcb755620 CR3: 00000001b82f0000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400