bisecting fixing commit since c076c79e03c6094e578df5d210fde808b3ad32e6 building syzkaller on 0487ea6f5d997a8363eba0d2eb0ea7a925444555 testing commit c076c79e03c6094e578df5d210fde808b3ad32e6 with gcc (GCC) 8.1.0 kernel signature: d86ec4d901f93f34d189025c436b19bd0f0a7e90dbc88014cbd8a94f273d7fbb all runs: crashed: BUG: corrupted list in l2cap_chan_put testing current HEAD 3207316b3beec7e38e5dbe2f463df0cec71e0b97 testing commit 3207316b3beec7e38e5dbe2f463df0cec71e0b97 with gcc (GCC) 8.1.0 kernel signature: 0c2c5530223489127df26408dfe6b37951f5c29c267c653eec569e95d6af8260 all runs: crashed: BUG: corrupted list in l2cap_chan_put revisions tested: 2, total time: 35m20.28377801s (build: 17m26.238027101s, test: 17m17.555731642s) the crash still happens on HEAD commit msg: Linux 4.19.164 crash: BUG: corrupted list in l2cap_chan_put bond0 (unregistering): Releasing backup interface bond_slave_0 bond0 (unregistering): Released all slaves IPVS: ftp: loaded support on port[0] = 21 list_del corruption, ffff8881d8be9608->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: 18903 Comm: kworker/u5:0 Not tainted 4.19.164-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+0x26/0x58 lib/list_debug.c:45 Code: 1d fe 0f 0b 4c 89 e2 48 89 de 48 c7 c7 00 8a 67 87 e8 26 63 1d fe 0f 0b 4c 89 ea 48 89 de 48 c7 c7 a0 89 67 87 e8 12 63 1d fe <0f> 0b 48 89 de 48 c7 c7 c0 8a 67 87 e8 01 63 1d fe 0f 0b 48 89 de RSP: 0018:ffff8881d363f6f8 EFLAGS: 00010282 RAX: 000000000000004e RBX: ffff8881d8be9608 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff87678700 RDI: ffffffff8a19da60 RBP: ffff8881d363f710 R08: ffffed103ed25081 R09: ffffed103ed25080 R10: ffffed103ed25080 R11: ffff8881f6928407 R12: dead000000000200 R13: dead000000000100 R14: ffff8881deeb7a40 R15: ffff8881deeb7ac0 FS: 0000000000000000(0000) GS:ffff8881f6900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000006e06c0 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:479 [inline] kref_put include/linux/kref.h:70 [inline] l2cap_chan_put+0x49/0x1a0 net/bluetooth/l2cap_core.c:496 l2cap_conless_channel net/bluetooth/l2cap_core.c:6982 [inline] l2cap_recv_frame+0xf29/0xa440 net/bluetooth/l2cap_core.c:7029 l2cap_recv_acldata+0x756/0x8a0 net/bluetooth/l2cap_core.c:7594 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 40e1554ed6da6559 ]--- 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 00 8a 67 87 e8 26 63 1d fe 0f 0b 4c 89 ea 48 89 de 48 c7 c7 a0 89 67 87 e8 12 63 1d fe <0f> 0b 48 89 de 48 c7 c7 c0 8a 67 87 e8 01 63 1d fe 0f 0b 48 89 de RSP: 0018:ffff8881d363f6f8 EFLAGS: 00010282 RAX: 000000000000004e RBX: ffff8881d8be9608 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff87678700 RDI: ffffffff8a19da60 RBP: ffff8881d363f710 R08: ffffed103ed25081 R09: ffffed103ed25080 R10: ffffed103ed25080 R11: ffff8881f6928407 R12: dead000000000200 R13: dead000000000100 R14: ffff8881deeb7a40 R15: ffff8881deeb7ac0 FS: 0000000000000000(0000) GS:ffff8881f6900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000006e06c0 CR3: 000000000846d006 CR4: 00000000001606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400