list_del corruption, ffff8801949a39a8->next is LIST_POISON1 (dead000000000100)
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:47!
invalid opcode: 0000 [#1] SMP KASAN
CPU: 1 PID: 9936 Comm: syz-executor2 Not tainted 4.18.0-rc6+ #160
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: 02 fe 0f 0b 4c 89 e2 48 89 de 48 c7 c7 60 67 1a 88 e8 ba 85 02 fe 0f 0b 4c 89 ea 48 89 de 48 c7 c7 00 67 1a 88 e8 a6 85 02 fe <0f> 0b 48 89 de 48 c7 c7 20 68 1a 88 e8 95 85 02 fe 0f 0b 48 89 de 
RSP: 0018:ffff8801931871c0 EFLAGS: 00010286
RAX: 000000000000004e RBX: ffff8801949a39a8 RCX: ffffc9000421e000
RDX: 0000000000000000 RSI: ffffffff816324b1 RDI: 0000000000000001
RBP: ffff8801931871d8 R08: ffff8801b2840240 R09: ffffed003b5e4fc0
R10: ffffed003b5e4fc0 R11: ffff8801daf27e07 R12: dead000000000200
R13: dead000000000100 R14: ffff8801949a39a8 R15: ffff8801949a39b0
FS:  00007fb310b49700(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb310b48db8 CR3: 00000001b7c7b000 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
 v9fs_session_init+0x21a/0x1a80 fs/9p/v9fs.c:400
 v9fs_mount+0x7c/0x900 fs/9p/vfs_super.c:135
 mount_fs+0xae/0x328 fs/super.c:1277
 vfs_kern_mount.part.34+0xdc/0x4e0 fs/namespace.c:1037
 vfs_kern_mount fs/namespace.c:1027 [inline]
 do_new_mount fs/namespace.c:2518 [inline]
 do_mount+0x581/0x30e0 fs/namespace.c:2848
 ksys_mount+0x12d/0x140 fs/namespace.c:3064
 __do_sys_mount fs/namespace.c:3078 [inline]
 __se_sys_mount fs/namespace.c:3075 [inline]
 __x64_sys_mount+0xbe/0x150 fs/namespace.c:3075
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x455ab9
Code: 1d ba fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 eb b9 fb ff c3 66 2e 0f 1f 84 00 00 00 00 
RSP: 002b:00007fb310b48c68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fb310b496d4 RCX: 0000000000455ab9
RDX: 00000000200002c0 RSI: 0000000020000280 RDI: 0000000000000000
RBP: 000000000072bf48 R08: 0000000020000300 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004c0201 R14: 00000000004cfe50 R15: 0000000000000001
Modules linked in:
Dumping ftrace buffer:
   (ftrace buffer empty)
---[ end trace bc10cc2887c64507 ]---
RIP: 0010:__list_del_entry_valid.cold.1+0x26/0x58 lib/list_debug.c:45
Code: 02 fe 0f 0b 4c 89 e2 48 89 de 48 c7 c7 60 67 1a 88 e8 ba 85 02 fe 0f 0b 4c 89 ea 48 89 de 48 c7 c7 00 67 1a 88 e8 a6 85 02 fe <0f> 0b 48 89 de 48 c7 c7 20 68 1a 88 e8 95 85 02 fe 0f 0b 48 89 de 
RSP: 0018:ffff8801931871c0 EFLAGS: 00010286
RAX: 000000000000004e RBX: ffff8801949a39a8 RCX: ffffc9000421e000
RDX: 0000000000000000 RSI: ffffffff816324b1 RDI: 0000000000000001
RBP: ffff8801931871d8 R08: ffff8801b2840240 R09: ffffed003b5e4fc0
R10: ffffed003b5e4fc0 R11: ffff8801daf27e07 R12: dead000000000200
R13: dead000000000100 R14: ffff8801949a39a8 R15: ffff8801949a39b0
FS:  00007fb310b49700(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb310b48db8 CR3: 00000001b7c7b000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400