syzbot

list_del corruption, ffff8881109be398->next is LIST_POISON1 (dead000000000100)
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:47!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 12644 Comm: syz-executor.3 Not tainted 5.10.82-syzkaller-00184-gbc8ae0e2afaf #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__list_del_entry_valid+0xc0/0x100 lib/list_debug.c:45
Code: df e8 c4 db 4e ff 48 8b 13 4c 39 f2 75 44 b0 01 5b 41 5c 41 5e 41 5f 5d c3 48 c7 c7 80 d9 49 85 4c 89 f6 31 c0 e8 17 47 fc fe <0f> 0b 48 c7 c7 e0 d9 49 85 4c 89 f6 31 c0 e8 04 47 fc fe 0f 0b 48
RSP: 0018:ffffc90004417428 EFLAGS: 00010246
RAX: 000000000000004e RBX: dead000000000100 RCX: 6bf3ee6aa9ff6b00
RDX: ffffc90002b78000 RSI: 000000000000147f RDI: 0000000000001480
RBP: ffffc90004417448 R08: ffffffff81544ce8 R09: ffffed103ee0a5d8
R10: ffffed103ee0a5d8 R11: 0000000000000000 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff8881109be398 R15: dead000000000122
FS:  00007fd80702b700(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd806fe9718 CR3: 0000000111fef000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __list_del_entry include/linux/list.h:132 [inline]
 list_del include/linux/list.h:146 [inline]
 p9_fd_cancelled+0x73/0x1d0 net/9p/trans_fd.c:722
 p9_client_flush+0x374/0x560 net/9p/client.c:677
 p9_client_rpc+0x837/0xa60 net/9p/client.c:784
 p9_client_version+0x179/0x680 net/9p/client.c:945
 p9_client_create+0x8f5/0xbb0 net/9p/client.c:1055
 v9fs_session_init+0x208/0x1a00 fs/9p/v9fs.c:406
 v9fs_mount+0x75/0x7e0 fs/9p/vfs_super.c:126
 legacy_get_tree+0xf0/0x190 fs/fs_context.c:592
 vfs_get_tree+0x89/0x270 fs/super.c:1549
 do_new_mount fs/namespace.c:2899 [inline]
 path_mount+0x1975/0x2ab0 fs/namespace.c:3229
 do_mount fs/namespace.c:3242 [inline]
 __do_sys_mount fs/namespace.c:3450 [inline]
 __se_sys_mount+0x2f7/0x3b0 fs/namespace.c:3427
 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3427
 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fd8078d5ae9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd80702b188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fd8079e9028 RCX: 00007fd8078d5ae9
RDX: 0000000020000140 RSI: 0000000020000200 RDI: 0000000000000000
RBP: 00007fd80792fff7 R08: 0000000020000580 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fffa3c7575f R14: 00007fd80702b300 R15: 0000000000022000
Modules linked in:
---[ end trace 05f602c27e2abe34 ]---
RIP: 0010:__list_del_entry_valid+0xc0/0x100 lib/list_debug.c:45
Code: df e8 c4 db 4e ff 48 8b 13 4c 39 f2 75 44 b0 01 5b 41 5c 41 5e 41 5f 5d c3 48 c7 c7 80 d9 49 85 4c 89 f6 31 c0 e8 17 47 fc fe <0f> 0b 48 c7 c7 e0 d9 49 85 4c 89 f6 31 c0 e8 04 47 fc fe 0f 0b 48
RSP: 0018:ffffc90004417428 EFLAGS: 00010246
RAX: 000000000000004e RBX: dead000000000100 RCX: 6bf3ee6aa9ff6b00
RDX: ffffc90002b78000 RSI: 000000000000147f RDI: 0000000000001480
RBP: ffffc90004417448 R08: ffffffff81544ce8 R09: ffffed103ee0a5d8
R10: ffffed103ee0a5d8 R11: 0000000000000000 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff8881109be398 R15: dead000000000122
FS:  00007fd80702b700(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd806fe9718 CR3: 0000000111fef000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400