Re: [syzbot] [nvme?] BUG: corrupted list in nvmet_fc_remove_port

[syzbot <syzbot+c98b21427617af7f547a@syzkaller.appspotmail.com>]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
BUG: corrupted list in nvmet_fc_remove_port

 non-slab/vmalloc memory
list_del corruption. prev->next should be ffff88805f6be020, but was 0000000000000000. (prev=ffffffff9aecd340)
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:64!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 6706 Comm: syz.1.55 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
RIP: 0010:__list_del_entry_valid_or_report+0x15a/0x190 lib/list_debug.c:62
Code: e8 8b f8 37 fd 43 80 3c 2c 00 74 08 4c 89 ff e8 4c bf 58 fd 49 8b 17 48 c7 c7 40 6e cc 8b 48 89 de 4c 89 f9 e8 27 88 4c fc 90 <0f> 0b 4c 89 f7 e8 5c f8 37 fd 43 80 3c 2c 00 74 08 4c 89 ff e8 1d
RSP: 0018:ffffc90005077c38 EFLAGS: 00010246
RAX: 000000000000006d RBX: ffff88805f6be020 RCX: 3022935dcdf04700
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000201 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed101708490b R12: 1ffffffff35d9a68
R13: dffffc0000000000 R14: ffffffff85f7e840 R15: ffffffff9aecd340
FS:  00007f556375d6c0(0000) GS:ffff8881249bb000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcf66ae41d8 CR3: 0000000035112000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __list_del_entry_valid include/linux/list.h:140 [inline]
 __list_del_entry include/linux/list.h:261 [inline]
 list_del include/linux/list.h:275 [inline]
 nvmet_fc_portentry_unbind drivers/nvme/target/fc.c:1288 [inline]
 nvmet_fc_remove_port+0x1fb/0x380 drivers/nvme/target/fc.c:2934
 nvmet_disable_port+0x13e/0x1f0 drivers/nvme/target/core.c:400
 nvmet_port_subsys_drop_link+0x1e8/0x210 drivers/nvme/target/configfs.c:1123
 configfs_unlink+0x44f/0x6b0 fs/configfs/symlink.c:258
 vfs_unlink+0x27b/0x6e0 fs/namei.c:5678
 filename_unlinkat+0x3d3/0x610 fs/namei.c:5748
 __do_sys_unlinkat fs/namei.c:5777 [inline]
 __se_sys_unlinkat+0x83/0x1a0 fs/namei.c:5769
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f556411e1d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f556375d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000107
RAX: ffffffffffffffda RBX: 00007f55643a6090 RCX: 00007f556411e1d9
RDX: 0000000000000000 RSI: 0000200000000780 RDI: ffffffffffffff9c
RBP: 00007f55641b5888 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f55643a6128 R14: 00007f55643a6090 R15: 00007ffde0760588
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__list_del_entry_valid_or_report+0x15a/0x190 lib/list_debug.c:62
Code: e8 8b f8 37 fd 43 80 3c 2c 00 74 08 4c 89 ff e8 4c bf 58 fd 49 8b 17 48 c7 c7 40 6e cc 8b 48 89 de 4c 89 f9 e8 27 88 4c fc 90 <0f> 0b 4c 89 f7 e8 5c f8 37 fd 43 80 3c 2c 00 74 08 4c 89 ff e8 1d
RSP: 0018:ffffc90005077c38 EFLAGS: 00010246
RAX: 000000000000006d RBX: ffff88805f6be020 RCX: 3022935dcdf04700
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000201 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed101708490b R12: 1ffffffff35d9a68
R13: dffffc0000000000 R14: ffffffff85f7e840 R15: ffffffff9aecd340
FS:  00007f556375d6c0(0000) GS:ffff8881249bb000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcf66c6f040 CR3: 0000000035112000 CR4: 00000000003526f0


Tested on:

commit:         24a19b95 Linux 7.3-rc7
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17e825d1580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=df4bbab1c2172b9f
dashboard link: https://syzkaller.appspot.com/bug?extid=c98b21427617af7f547a
compiler:       Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
patch:          https://syzkaller.appspot.com/x/patch.diff?x=12c690a5580000