syzbot

 non-paged memory
list_del corruption, ffff88802fd8c610->next is LIST_POISON1 (dead000000000100)
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:58!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 16622 Comm: syz.5.2615 Not tainted 6.16.0-rc2-syzkaller-00082-gfb4d33ab452e #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:__list_del_entry_valid_or_report+0x10e/0x190 lib/list_debug.c:56
Code: 00 8f e2 8b 48 89 de e8 70 f1 5f fc 90 0f 0b 4c 89 e7 e8 05 66 3b fd 48 c7 c7 60 8f e2 8b 48 89 de 4c 89 e2 e8 53 f1 5f fc 90 <0f> 0b 4c 89 e7 e8 e8 65 3b fd 48 c7 c7 c0 8f e2 8b 48 89 de 4c 89
RSP: 0018:ffffc900045cf508 EFLAGS: 00010246
RAX: 000000000000004e RBX: ffff88802fd8c610 RCX: 0a119e2a79481100
RDX: ffffc9000d1fd000 RSI: 0000000000008263 RDI: 0000000000008264
RBP: 0000000000000005 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff1bfa9ec R12: dead000000000100
R13: dffffc0000000000 R14: dead000000000100 R15: dead000000000122
FS:  00007efed21316c0(0000) GS:ffff888125c51000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f339eae56c0 CR3: 000000003eaa9000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 __list_del_entry_valid include/linux/list.h:124 [inline]
 __list_del_entry include/linux/list.h:215 [inline]
 list_del include/linux/list.h:229 [inline]
 p9_fd_cancelled+0x98/0x210 net/9p/trans_fd.c:740
 p9_client_flush+0x2e7/0x390 net/9p/client.c:618
 p9_client_rpc+0x8a6/0xa70 net/9p/client.c:741
 p9_client_version net/9p/client.c:-1 [inline]
 p9_client_create+0x954/0xfe0 net/9p/client.c:1036
 v9fs_session_init+0x1d7/0x19a0 fs/9p/v9fs.c:410
 v9fs_mount+0xc8/0xa10 fs/9p/vfs_super.c:122
 legacy_get_tree+0xfd/0x1a0 fs/fs_context.c:666
 vfs_get_tree+0x92/0x2b0 fs/super.c:1804
 do_new_mount+0x24a/0xa40 fs/namespace.c:3885
 do_mount fs/namespace.c:4222 [inline]
 __do_sys_mount fs/namespace.c:4433 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4410
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efed138e929
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007efed2131038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007efed15b5fa0 RCX: 00007efed138e929
RDX: 0000200000000040 RSI: 0000200000000000 RDI: 0000000000000000
RBP: 00007efed1410b39 R08: 0000200000000280 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007efed15b5fa0 R15: 00007fff796752e8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__list_del_entry_valid_or_report+0x10e/0x190 lib/list_debug.c:56
Code: 00 8f e2 8b 48 89 de e8 70 f1 5f fc 90 0f 0b 4c 89 e7 e8 05 66 3b fd 48 c7 c7 60 8f e2 8b 48 89 de 4c 89 e2 e8 53 f1 5f fc 90 <0f> 0b 4c 89 e7 e8 e8 65 3b fd 48 c7 c7 c0 8f e2 8b 48 89 de 4c 89
RSP: 0018:ffffc900045cf508 EFLAGS: 00010246
RAX: 000000000000004e RBX: ffff88802fd8c610 RCX: 0a119e2a79481100
RDX: ffffc9000d1fd000 RSI: 0000000000008263 RDI: 0000000000008264
RBP: 0000000000000005 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff1bfa9ec R12: dead000000000100
R13: dffffc0000000000 R14: dead000000000100 R15: dead000000000122
FS:  00007efed21316c0(0000) GS:ffff888125c51000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f339eae56c0 CR3: 000000003eaa9000 CR4: 0000000000350ef0