bisecting fixing commit since c076c79e03c6094e578df5d210fde808b3ad32e6
building syzkaller on 0487ea6f5d997a8363eba0d2eb0ea7a925444555
testing commit c076c79e03c6094e578df5d210fde808b3ad32e6
compiler: gcc version 8.4.1 20210217 (GCC)
kernel signature: b6e08b524d90b0e705af5045826b01e9c434218bb314becb0128e5731dbe1451
all runs: crashed: BUG: corrupted list in l2cap_chan_put
testing current HEAD 59456c9cc40c8f75b5a7efa0fe1f211d9c6fcaf1
testing commit 59456c9cc40c8f75b5a7efa0fe1f211d9c6fcaf1
compiler: gcc version 8.4.1 20210217 (GCC)
kernel signature: b3f36219beb34573626b71228843869a4d51101874a5296bda0c96c1a776cbf4
all runs: crashed: BUG: corrupted list in l2cap_chan_put
revisions tested: 2, total time: 40m15.556559347s (build: 21m12.594770874s, test: 18m23.210524311s)
the crash still happens on HEAD
commit msg: Linux 4.19.204
crash: BUG: corrupted list in l2cap_chan_put
bond0 (unregistering): Releasing backup interface bond_slave_0
bond0 (unregistering): Released all slaves
Bluetooth: hci0: command 0x041b tx timeout
list_del corruption, ffff8881df00a488->next is LIST_POISON1 (dead000000000100)
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:47!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 7265 Comm: kworker/u5:2 Not tainted 4.19.204-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: hci0 hci_rx_work
RIP: 0010:__list_del_entry_valid.cold.1+0x26/0x4a lib/list_debug.c:45
Code: f9 ff 0f 0b 4c 89 e2 48 89 de 48 c7 c7 e0 a6 67 87 e8 cb 68 f9 ff 0f 0b 4c 89 ea 48 89 de 48 c7 c7 80 a6 67 87 e8 b7 68 f9 ff <0f> 0b 48 89 de 48 c7 c7 a0 a7 67 87 e8 a6 68 f9 ff 0f 0b 48 89 de
RSP: 0018:ffff8881dcca76f8 EFLAGS: 00010282
RAX: 000000000000004e RBX: ffff8881df00a488 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8767a3e0 RDI: ffffffff8a19faa0
RBP: ffff8881dcca7710 R08: ffffed103ed25081 R09: ffffed103ed25080
R10: ffffed103ed25080 R11: ffff8881f6928407 R12: dead000000000200
R13: dead000000000100 R14: ffff8881c33a7980 R15: ffff8881c33a7a00
FS:  0000000000000000(0000) GS:ffff8881f6900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000754608 CR3: 000000000846d006 CR4: 00000000001606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __list_del_entry include/linux/list.h:117 [inline]
 list_del include/linux/list.h:125 [inline]
 l2cap_chan_destroy net/bluetooth/l2cap_core.c:481 [inline]
 kref_put include/linux/kref.h:70 [inline]
 l2cap_chan_put+0x49/0x1a0 net/bluetooth/l2cap_core.c:498
 l2cap_conless_channel net/bluetooth/l2cap_core.c:6986 [inline]
 l2cap_recv_frame+0xf29/0xa430 net/bluetooth/l2cap_core.c:7033
 l2cap_recv_acldata+0x756/0x8a0 net/bluetooth/l2cap_core.c:7598
 hci_acldata_packet net/bluetooth/hci_core.c:4185 [inline]
 hci_rx_work+0x5d6/0x8f0 net/bluetooth/hci_core.c:4371
 process_one_work+0x7b9/0x15a0 kernel/workqueue.c:2153
 worker_thread+0x85/0xb60 kernel/workqueue.c:2296
 kthread+0x347/0x410 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Modules linked in:
---[ end trace c8161ab86240c71c ]---
RIP: 0010:__list_del_entry_valid.cold.1+0x26/0x4a lib/list_debug.c:45
Code: f9 ff 0f 0b 4c 89 e2 48 89 de 48 c7 c7 e0 a6 67 87 e8 cb 68 f9 ff 0f 0b 4c 89 ea 48 89 de 48 c7 c7 80 a6 67 87 e8 b7 68 f9 ff <0f> 0b 48 89 de 48 c7 c7 a0 a7 67 87 e8 a6 68 f9 ff 0f 0b 48 89 de
RSP: 0018:ffff8881dcca76f8 EFLAGS: 00010282
RAX: 000000000000004e RBX: ffff8881df00a488 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8767a3e0 RDI: ffffffff8a19faa0
RBP: ffff8881dcca7710 R08: ffffed103ed25081 R09: ffffed103ed25080
R10: ffffed103ed25080 R11: ffff8881f6928407 R12: dead000000000200
R13: dead000000000100 R14: ffff8881c33a7980 R15: ffff8881c33a7a00
FS:  0000000000000000(0000) GS:ffff8881f6900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000754608 CR3: 000000000846d006 CR4: 00000000001606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	f9                   	stc    
   1:	ff 0f                	decl   (%rdi)
   3:	0b 4c 89 e2          	or     -0x1e(%rcx,%rcx,4),%ecx
   7:	48 89 de             	mov    %rbx,%rsi
   a:	48 c7 c7 e0 a6 67 87 	mov    $0xffffffff8767a6e0,%rdi
  11:	e8 cb 68 f9 ff       	callq  0xfff968e1
  16:	0f 0b                	ud2    
  18:	4c 89 ea             	mov    %r13,%rdx
  1b:	48 89 de             	mov    %rbx,%rsi
  1e:	48 c7 c7 80 a6 67 87 	mov    $0xffffffff8767a680,%rdi
  25:	e8 b7 68 f9 ff       	callq  0xfff968e1
  2a:	0f 0b                	ud2     <-- trapping instruction
  2c:	48 89 de             	mov    %rbx,%rsi
  2f:	48 c7 c7 a0 a7 67 87 	mov    $0xffffffff8767a7a0,%rdi
  36:	e8 a6 68 f9 ff       	callq  0xfff968e1
  3b:	0f 0b                	ud2    
  3d:	48 89 de             	mov    %rbx,%rsi