bisecting fixing commit since c076c79e03c6094e578df5d210fde808b3ad32e6
building syzkaller on 4ca1c0ea446d2c09b1fb49a85ae645e3754f1058
testing commit c076c79e03c6094e578df5d210fde808b3ad32e6 with gcc (GCC) 8.1.0
kernel signature: 8e688b4b0cf43d535a09b5e1d4ed8627b944c669d5a59b49aec0ce19e224cb23
all runs: crashed: BUG: corrupted list in l2cap_chan_put
testing current HEAD c37da90efff5f183bea6ae4c2af33571f61fe317
testing commit c37da90efff5f183bea6ae4c2af33571f61fe317 with gcc (GCC) 8.1.0
kernel signature: 82cda2d47ae078fb078f15afc8b887db50c3aab818147310c8402dc166aa52e0
all runs: crashed: BUG: corrupted list in l2cap_chan_put
revisions tested: 2, total time: 36m36.92932572s (build: 20m39.646405163s, test: 14m27.271512519s)
the crash still happens on HEAD
commit msg: Linux 4.19.143
crash: BUG: corrupted list in l2cap_chan_put
Bluetooth: hci5: command 0x0419 tx timeout
Bluetooth: hci4: command 0x0419 tx timeout
Bluetooth: hci3: command 0x0419 tx timeout
list_del corruption, ffff8880a4ba7288->next is LIST_POISON1 (dead000000000100)
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:47!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 29896 Comm: kworker/u5:0 Not tainted 4.19.143-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: hci1 hci_rx_work
RIP: 0010:__list_del_entry_valid.cold.1+0x26/0x58 lib/list_debug.c:45
Code: 1d fe 0f 0b 4c 89 e2 48 89 de 48 c7 c7 a0 88 67 87 e8 d6 dc 1d fe 0f 0b 4c 89 ea 48 89 de 48 c7 c7 40 88 67 87 e8 c2 dc 1d fe <0f> 0b 48 89 de 48 c7 c7 60 89 67 87 e8 b1 dc 1d fe 0f 0b 48 89 de
RSP: 0018:ffff88806f8376f8 EFLAGS: 00010282
RAX: 000000000000004e RBX: ffff8880a4ba7288 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff876785a0 RDI: ffffffff8a1a3a60
RBP: ffff88806f837710 R08: ffffed1015d45081 R09: ffffed1015d45080
R10: ffffed1015d45080 R11: ffff8880aea28407 R12: dead000000000200
R13: dead000000000100 R14: ffff88808d9f2840 R15: ffff88808d9f28c0
FS:  0000000000000000(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000088ae8000 CR4: 00000000001406f0
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:476 [inline]
 kref_put include/linux/kref.h:70 [inline]
 l2cap_chan_put+0x49/0x1a0 net/bluetooth/l2cap_core.c:493
 l2cap_conless_channel net/bluetooth/l2cap_core.c:6976 [inline]
 l2cap_recv_frame+0xf29/0xa490 net/bluetooth/l2cap_core.c:7023
 l2cap_recv_acldata+0x756/0x8a0 net/bluetooth/l2cap_core.c:7588
 hci_acldata_packet net/bluetooth/hci_core.c:4178 [inline]
 hci_rx_work+0x5e1/0x8e0 net/bluetooth/hci_core.c:4364
 process_one_work+0x7b9/0x15a0 kernel/workqueue.c:2155
 worker_thread+0x85/0xb60 kernel/workqueue.c:2298
 kthread+0x347/0x410 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Modules linked in:
---[ end trace e62a5f595f05d0f0 ]---
RIP: 0010:__list_del_entry_valid.cold.1+0x26/0x58 lib/list_debug.c:45
Code: 1d fe 0f 0b 4c 89 e2 48 89 de 48 c7 c7 a0 88 67 87 e8 d6 dc 1d fe 0f 0b 4c 89 ea 48 89 de 48 c7 c7 40 88 67 87 e8 c2 dc 1d fe <0f> 0b 48 89 de 48 c7 c7 60 89 67 87 e8 b1 dc 1d fe 0f 0b 48 89 de
RSP: 0018:ffff88806f8376f8 EFLAGS: 00010282
RAX: 000000000000004e RBX: ffff8880a4ba7288 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff876785a0 RDI: ffffffff8a1a3a60
RBP: ffff88806f837710 R08: ffffed1015d45081 R09: ffffed1015d45080
R10: ffffed1015d45080 R11: ffff8880aea28407 R12: dead000000000200
R13: dead000000000100 R14: ffff88808d9f2840 R15: ffff88808d9f28c0
FS:  0000000000000000(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000088ae8000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400