Re: [syzbot] [bluetooth?] BUG: corrupted list in hci_chan_del (2)

[syzbot <syzbot+10bd8fe6741eedd2be2e@syzkaller.appspotmail.com>]

Hello,

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

 non-paged memory
list_del corruption, ffff88801251b500->prev is LIST_POISON2 (dead000000000122)
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:61!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 0 UID: 0 PID: 6801 Comm: syz.0.32 Not tainted 6.14.0-rc1-next-20250207-syzkaller-02219-ged58d103e6da-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
RIP: 0010:__list_del_entry_valid_or_report+0x12c/0x190 lib/list_debug.c:59
Code: 8c 4c 89 fe 48 89 da e8 a2 63 36 fc 90 0f 0b 48 89 df e8 27 e0 13 fd 48 c7 c7 a0 ce 60 8c 4c 89 fe 48 89 da e8 85 63 36 fc 90 <0f> 0b 4c 89 e7 e8 0a e0 13 fd 42 80 3c 2b 00 74 08 4c 89 e7 e8 db
RSP: 0018:ffffc900033b7878 EFLAGS: 00010246
RAX: 000000000000004e RBX: dead000000000122 RCX: 3b04728f07e88400
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: dffffc0000000000 R08: ffffffff819f3f6c R09: fffffbfff1cfa5b8
R10: dffffc0000000000 R11: fffffbfff1cfa5b8 R12: dead000000000122
R13: dffffc0000000000 R14: ffff8880285d88d8 R15: ffff88801251b500
FS:  00007fe19c9ff6c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe19c9ddf98 CR3: 00000000673a2000 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_rcu include/linux/rculist.h:168 [inline]
 hci_chan_del+0x70/0x1b0 net/bluetooth/hci_conn.c:2858
 l2cap_conn_free net/bluetooth/l2cap_core.c:1805 [inline]
 kref_put include/linux/kref.h:65 [inline]
 l2cap_conn_put+0x70/0xe0 net/bluetooth/l2cap_core.c:1819
 l2cap_sock_shutdown+0xa6d/0x1070 net/bluetooth/l2cap_sock.c:1376
 l2cap_sock_release+0x79/0x1d0 net/bluetooth/l2cap_sock.c:1415
 __sock_release net/socket.c:647 [inline]
 sock_close+0xbc/0x240 net/socket.c:1398
 __fput+0x3e9/0x9f0 fs/file_table.c:464
 task_work_run+0x24f/0x310 kernel/task_work.c:227
 get_signal+0x15f7/0x1750 kernel/signal.c:2809
 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe19bb8cda9
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:00007fe19c9ff038 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: fffffffffffffffc RBX: 00007fe19bda5fa0 RCX: 00007fe19bb8cda9
RDX: 000000000000000e RSI: 0000000020000100 RDI: 0000000000000004
RBP: 00007fe19bc0e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fe19bda5fa0 R15: 00007ffdbd7c9148
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__list_del_entry_valid_or_report+0x12c/0x190 lib/list_debug.c:59
Code: 8c 4c 89 fe 48 89 da e8 a2 63 36 fc 90 0f 0b 48 89 df e8 27 e0 13 fd 48 c7 c7 a0 ce 60 8c 4c 89 fe 48 89 da e8 85 63 36 fc 90 <0f> 0b 4c 89 e7 e8 0a e0 13 fd 42 80 3c 2b 00 74 08 4c 89 e7 e8 db
RSP: 0018:ffffc900033b7878 EFLAGS: 00010246
RAX: 000000000000004e RBX: dead000000000122 RCX: 3b04728f07e88400
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: dffffc0000000000 R08: ffffffff819f3f6c R09: fffffbfff1cfa5b8
R10: dffffc0000000000 R11: fffffbfff1cfa5b8 R12: dead000000000122
R13: dffffc0000000000 R14: ffff8880285d88d8 R15: ffff88801251b500
FS:  00007fe19c9ff6c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe19c9ddf98 CR3: 00000000673a2000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


Tested on:

commit:         ed58d103 Add linux-next specific files for 20250207
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=14509df8580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=244a34ec1429746
dashboard link: https://syzkaller.appspot.com/bug?extid=10bd8fe6741eedd2be2e
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=15ff1df8580000