syzbot

 non-paged memory
list_del corruption, ffff8880343ea2e0->next is LIST_POISON1 (dead000000000100)
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:58!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 7067 Comm: syz.4.289 Not tainted 6.15.0-rc1-syzkaller-00246-g900241a5cc15 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:__list_del_entry_valid_or_report+0x10f/0x190 lib/list_debug.c:56
Code: e0 e3 a0 8c 4c 89 fe e8 df f5 22 fc 90 0f 0b 48 89 df e8 34 e9 03 fd 48 c7 c7 40 e4 a0 8c 4c 89 fe 48 89 da e8 c2 f5 22 fc 90 <0f> 0b 48 89 df e8 17 e9 03 fd 48 c7 c7 a0 e4 a0 8c 4c 89 fe 48 89
RSP: 0018:ffffc9000480f708 EFLAGS: 00010246
RAX: 000000000000004e RBX: dead000000000100 RCX: 857d98dd08f2ec00
RDX: ffffc9000cd45000 RSI: 0000000000008b7e RDI: 0000000000008b7f
RBP: ffff8880343ea220 R08: ffffffff81a2932c R09: fffffbfff1d7a970
R10: dffffc0000000000 R11: fffffbfff1d7a970 R12: dead000000000122
R13: dffffc0000000000 R14: dead000000000100 R15: ffff8880343ea2e0
FS:  00007fbb8eb616c0(0000) GS:ffff888124fc9000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3001dffc CR3: 0000000021750000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
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+0x99/0x220 net/9p/trans_fd.c:740
 p9_client_flush+0x3cd/0x550 net/9p/client.c:618
 p9_client_rpc+0x8ff/0xad0 net/9p/client.c:741
 p9_client_stat+0x112/0x290 net/9p/client.c:1747
 v9fs_inode_from_fid+0x88/0x550 fs/9p/vfs_inode.c:456
 v9fs_get_new_inode_from_fid fs/9p/v9fs.h:253 [inline]
 v9fs_mount+0x6fa/0xaa0 fs/9p/vfs_super.c:142
 legacy_get_tree+0xee/0x190 fs/fs_context.c:662
 vfs_get_tree+0x90/0x2b0 fs/super.c:1759
 do_new_mount+0x2cf/0xb70 fs/namespace.c:3879
 do_mount fs/namespace.c:4219 [inline]
 __do_sys_mount fs/namespace.c:4430 [inline]
 __se_sys_mount+0x38c/0x400 fs/namespace.c:4407
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbb8dd8d169
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:00007fbb8eb61038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fbb8dfa5fa0 RCX: 00007fbb8dd8d169
RDX: 0000200000000080 RSI: 00002000000002c0 RDI: 0000000000000000
RBP: 00007fbb8de0e990 R08: 0000200000000400 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fbb8dfa5fa0 R15: 00007ffd9b8c3b28
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__list_del_entry_valid_or_report+0x10f/0x190 lib/list_debug.c:56
Code: e0 e3 a0 8c 4c 89 fe e8 df f5 22 fc 90 0f 0b 48 89 df e8 34 e9 03 fd 48 c7 c7 40 e4 a0 8c 4c 89 fe 48 89 da e8 c2 f5 22 fc 90 <0f> 0b 48 89 df e8 17 e9 03 fd 48 c7 c7 a0 e4 a0 8c 4c 89 fe 48 89
RSP: 0018:ffffc9000480f708 EFLAGS: 00010246
RAX: 000000000000004e RBX: dead000000000100 RCX: 857d98dd08f2ec00
RDX: ffffc9000cd45000 RSI: 0000000000008b7e RDI: 0000000000008b7f
RBP: ffff8880343ea220 R08: ffffffff81a2932c R09: fffffbfff1d7a970
R10: dffffc0000000000 R11: fffffbfff1d7a970 R12: dead000000000122
R13: dffffc0000000000 R14: dead000000000100 R15: ffff8880343ea2e0
FS:  00007fbb8eb616c0(0000) GS:ffff888124fc9000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3001dffc CR3: 0000000021750000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400