bisecting fixing commit since 2f166cdcf8a92fcf85524f2b5526cb28e16f0a60 building syzkaller on abf9ba4fc75d9b29af15625d44dcfc1360fad3b7 testing commit 2f166cdcf8a92fcf85524f2b5526cb28e16f0a60 with gcc (GCC) 8.1.0 kernel signature: 6a4af53e2c222dc806d37d0865a46e702bca904de5a52654281878100d0b1120 run #0: crashed: inconsistent lock state in sco_sock_timeout run #1: crashed: inconsistent lock state in sco_sock_timeout run #2: crashed: inconsistent lock state in sco_conn_del run #3: crashed: inconsistent lock state in sco_sock_timeout run #4: crashed: inconsistent lock state in sco_sock_timeout run #5: crashed: inconsistent lock state in sco_sock_timeout run #6: crashed: inconsistent lock state in sco_conn_del run #7: crashed: inconsistent lock state in sco_conn_del run #8: crashed: inconsistent lock state in sco_conn_del run #9: crashed: inconsistent lock state in sco_conn_del testing current HEAD bae31eef2a167ef160ab2703b6a2f5bbecd98d92 testing commit bae31eef2a167ef160ab2703b6a2f5bbecd98d92 with gcc (GCC) 8.1.0 kernel signature: 6c945b1deed86f6e478722c55827603e2091a4ad6e02b83f01f76fa9849768a6 run #0: crashed: inconsistent lock state in sco_sock_timeout run #1: crashed: inconsistent lock state in sco_conn_del run #2: crashed: inconsistent lock state in sco_conn_del run #3: crashed: inconsistent lock state in sco_sock_timeout run #4: crashed: inconsistent lock state in sco_sock_timeout run #5: crashed: inconsistent lock state in sco_sock_timeout run #6: crashed: inconsistent lock state in sco_conn_del run #7: crashed: inconsistent lock state in sco_conn_del run #8: crashed: inconsistent lock state in sco_conn_del run #9: crashed: inconsistent lock state in sco_conn_del revisions tested: 2, total time: 30m55.788695317s (build: 17m40.384687347s, test: 12m27.997312504s) the crash still happens on HEAD commit msg: Linux 4.14.200 crash: inconsistent lock state in sco_conn_del IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready Bluetooth: hci1 command 0x0409 tx timeout ================================ WARNING: inconsistent lock state 4.14.200-syzkaller #0 Not tainted -------------------------------- inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. syz-executor.0/30830 [HC0[0]:SC0[0]:HE1:SE1] takes: (slock-AF_BLUETOOTH-BTPROTO_SCO){+.?.}, at: [] spin_lock include/linux/spinlock.h:317 [inline] (slock-AF_BLUETOOTH-BTPROTO_SCO){+.?.}, at: [] sco_conn_del.isra.1+0x96/0x130 net/bluetooth/sco.c:175 {IN-SOFTIRQ-W} state was registered at: mark_irqflags kernel/locking/lockdep.c:3072 [inline] __lock_acquire+0x1241/0x42d0 kernel/locking/lockdep.c:3448 lock_acquire+0x17e/0x3e0 kernel/locking/lockdep.c:3998 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2d/0x40 kernel/locking/spinlock.c:152 spin_lock include/linux/spinlock.h:317 [inline] sco_sock_timeout+0x19/0xb0 net/bluetooth/sco.c:82 call_timer_fn+0x142/0x570 kernel/time/timer.c:1280 expire_timers+0x299/0x440 kernel/time/timer.c:1319 __run_timers kernel/time/timer.c:1644 [inline] run_timer_softirq+0x1cd/0x540 kernel/time/timer.c:1657 __do_softirq+0x246/0x9b5 kernel/softirq.c:288 invoke_softirq kernel/softirq.c:368 [inline] irq_exit+0x15f/0x1a0 kernel/softirq.c:409 exiting_irq arch/x86/include/asm/apic.h:648 [inline] smp_apic_timer_interrupt+0x145/0x5d0 arch/x86/kernel/apic/apic.c:1102 apic_timer_interrupt+0x9a/0xa0 arch/x86/entry/entry_64.S:793 native_safe_halt+0x12/0x20 arch/x86/include/asm/irqflags.h:60 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline] default_idle+0x4f/0x370 arch/x86/kernel/process.c:558 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:549 default_idle_call+0x6d/0x90 kernel/sched/idle.c:98 cpuidle_idle_call kernel/sched/idle.c:156 [inline] do_idle+0x317/0x3e0 kernel/sched/idle.c:246 cpu_startup_entry+0x18/0x20 kernel/sched/idle.c:351 start_secondary+0x391/0x490 arch/x86/kernel/smpboot.c:272 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:240 irq event stamp: 1087 hardirqs last enabled at (1087): [] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] hardirqs last enabled at (1087): [] _raw_spin_unlock_irq+0x27/0x90 kernel/locking/spinlock.c:200 hardirqs last disabled at (1086): [] __raw_spin_lock_irq include/linux/spinlock_api_smp.h:126 [inline] hardirqs last disabled at (1086): [] _raw_spin_lock_irq+0x3c/0x90 kernel/locking/spinlock.c:168 softirqs last enabled at (0): [] copy_process.part.6+0x1395/0x6bd0 kernel/fork.c:1714 softirqs last disabled at (0): [< (null)>] (null) other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(slock-AF_BLUETOOTH-BTPROTO_SCO); lock(slock-AF_BLUETOOTH-BTPROTO_SCO); *** DEADLOCK *** 3 locks held by syz-executor.0/30830: #0: (&hdev->req_lock){+.+.}, at: [] hci_dev_do_close+0x10a/0xb10 net/bluetooth/hci_core.c:1576 #1: (&hdev->lock){+.+.}, at: [] hci_dev_do_close+0x202/0xb10 net/bluetooth/hci_core.c:1607 #2: (hci_cb_list_lock){+.+.}, at: [] hci_disconn_cfm include/net/bluetooth/hci_core.h:1223 [inline] #2: (hci_cb_list_lock){+.+.}, at: [] hci_conn_hash_flush+0xc7/0x200 net/bluetooth/hci_conn.c:1376 stack backtrace: CPU: 1 PID: 30830 Comm: syz-executor.0 Not tainted 4.14.200-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x14b/0x1f1 lib/dump_stack.c:58 print_usage_bug.cold.46+0x433/0x563 kernel/locking/lockdep.c:2589 valid_state kernel/locking/lockdep.c:2602 [inline] mark_lock_irq kernel/locking/lockdep.c:2796 [inline] mark_lock+0xc00/0x11a0 kernel/locking/lockdep.c:3194 mark_irqflags kernel/locking/lockdep.c:3090 [inline] __lock_acquire+0x6d9/0x42d0 kernel/locking/lockdep.c:3448 lock_acquire+0x17e/0x3e0 kernel/locking/lockdep.c:3998 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2d/0x40 kernel/locking/spinlock.c:152 spin_lock include/linux/spinlock.h:317 [inline] sco_conn_del.isra.1+0x96/0x130 net/bluetooth/sco.c:175 sco_disconn_cfm+0x50/0x70 net/bluetooth/sco.c:1134 hci_disconn_cfm include/net/bluetooth/hci_core.h:1226 [inline] hci_conn_hash_flush+0x10b/0x200 net/bluetooth/hci_conn.c:1376 hci_dev_do_close+0x47a/0xb10 net/bluetooth/hci_core.c:1620 hci_unregister_dev+0x163/0x790 net/bluetooth/hci_core.c:3191 vhci_release+0x6b/0xe0 drivers/bluetooth/hci_vhci.c:354 __fput+0x232/0x740 fs/file_table.c:210 ____fput+0x9/0x10 fs/file_table.c:244 task_work_run+0xe5/0x170 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x953/0x2c40 kernel/exit.c:865 do_group_exit+0xf8/0x2c0 kernel/exit.c:962 get_signal+0x2f6/0x1ab0 kernel/signal.c:2423 do_signal+0x7f/0x18b0 arch/x86/kernel/signal.c:814 exit_to_usermode_loop+0x11e/0x190 arch/x86/entry/common.c:160 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x416/0x5b0 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45d5b9 RSP: 002b:00007fba8f03ccf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 000000000118cf48 RCX: 000000000045d5b9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000118cf48 RBP: 000000000118cf40 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c R13: 00007ffc32be61ef R14: 00007fba8f03d9c0 R15: 000000000118cf4c Bluetooth: hci1 command 0x041b tx timeout batman_adv: batadv0: Interface deactivated: batadv_slave_0 batman_adv: batadv0: Removing interface: batadv_slave_0 batman_adv: batadv0: Interface deactivated: batadv_slave_1 batman_adv: batadv0: Removing interface: batadv_slave_1 device bridge_slave_1 left promiscuous mode bridge0: port 2(bridge_slave_1) entered disabled state device bridge_slave_0 left promiscuous mode bridge0: port 1(bridge_slave_0) entered disabled state device veth1_macvtap left promiscuous mode device veth0_macvtap left promiscuous mode device veth1_vlan left promiscuous mode device veth0_vlan left promiscuous mode device hsr_slave_1 left promiscuous mode device hsr_slave_0 left promiscuous mode team0 (unregistering): Port device team_slave_1 removed team0 (unregistering): Port device team_slave_0 removed bond0 (unregistering): Releasing backup interface bond_slave_1 bond0 (unregistering): Releasing backup interface bond_slave_0 bond0 (unregistering): Released all slaves IPVS: ftp: loaded support on port[0] = 21 chnl_net:caif_netlink_parms(): no params data found bridge0: port 1(bridge_slave_0) entered blocking state bridge0: port 1(bridge_slave_0) entered disabled state device bridge_slave_0 entered promiscuous mode bridge0: port 2(bridge_slave_1) entered blocking state bridge0: port 2(bridge_slave_1) entered disabled state device bridge_slave_1 entered promiscuous mode bond0: Enslaving bond_slave_0 as an active interface with an up link bond0: Enslaving bond_slave_1 as an active interface with an up link IPv6: ADDRCONF(NETDEV_UP): team_slave_0: link is not ready team0: Port device team_slave_0 added IPv6: ADDRCONF(NETDEV_UP): team_slave_1: link is not ready team0: Port device team_slave_1 added batman_adv: batadv0: Adding interface: batadv_slave_0 batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem. batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active batman_adv: batadv0: Adding interface: batadv_slave_1 batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem. batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active IPv6: ADDRCONF(NETDEV_UP): bridge_slave_0: link is not ready IPv6: ADDRCONF(NETDEV_UP): bridge_slave_1: link is not ready device hsr_slave_0 entered promiscuous mode device hsr_slave_1 entered promiscuous mode IPv6: ADDRCONF(NETDEV_UP): hsr_slave_0: link is not ready IPv6: ADDRCONF(NETDEV_UP): hsr_slave_1: link is not ready bridge0: port 2(bridge_slave_1) entered blocking state bridge0: port 2(bridge_slave_1) entered forwarding state bridge0: port 1(bridge_slave_0) entered blocking state bridge0: port 1(bridge_slave_0) entered forwarding state 8021q: adding VLAN 0 to HW filter on device bond0 IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready bridge0: port 1(bridge_slave_0) entered disabled state bridge0: port 2(bridge_slave_1) entered disabled state IPv6: ADDRCONF(NETDEV_UP): team0: link is not ready 8021q: adding VLAN 0 to HW filter on device team0 IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready bridge0: port 1(bridge_slave_0) entered blocking state bridge0: port 1(bridge_slave_0) entered forwarding state IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready bridge0: port 2(bridge_slave_1) entered blocking state bridge0: port 2(bridge_slave_1) entered forwarding state IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): team0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_1: link becomes ready hsr0: Slave A (hsr_slave_0) is not up; please bring it up to get a fully working HSR network hsr0: Slave B (hsr_slave_1) is not up; please bring it up to get a fully working HSR network IPv6: ADDRCONF(NETDEV_UP): hsr0: link is not ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr0: link becomes ready IPv6: ADDRCONF(NETDEV_UP): vxcan0: link is not ready 8021q: adding VLAN 0 to HW filter on device batadv0 IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready IPv6: ADDRCONF(NETDEV_UP): veth0_virt_wifi: link is not ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_virt_wifi: link becomes ready IPv6: ADDRCONF(NETDEV_UP): veth0_vlan: link is not ready IPv6: ADDRCONF(NETDEV_UP): vlan0: link is not ready IPv6: ADDRCONF(NETDEV_UP): vlan1: link is not ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_vlan: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vlan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vlan1: link becomes ready device veth0_vlan entered promiscuous mode device veth1_vlan entered promiscuous mode IPv6: ADDRCONF(NETDEV_UP): macvlan0: link is not ready IPv6: ADDRCONF(NETDEV_UP): macvlan1: link is not ready IPv6: ADDRCONF(NETDEV_UP): veth0_macvtap: link is not ready IPv6: ADDRCONF(NETDEV_CHANGE): macvlan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): macvlan1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_macvtap: link becomes ready device veth0_macvtap entered promiscuous mode IPv6: ADDRCONF(NETDEV_UP): macvtap0: link is not ready Bluetooth: hci1 command 0x040f tx timeout device veth1_macvtap entered promiscuous mode IPv6: ADDRCONF(NETDEV_UP): veth0_to_batadv: link is not ready IPv6: ADDRCONF(NETDEV_UP): veth1_to_batadv: link is not ready batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! batman_adv: batadv0: Interface activated: batadv_slave_0 IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_batadv: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): macvtap0: link becomes ready batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_1 batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems! IPv6: ADDRCONF(NETDEV_UP): batadv_slave_1: link is not ready batman_adv: batadv0: Interface activated: batadv_slave_1 IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready Bluetooth: hci5 command 0x0409 tx timeout Bluetooth: hci1 command 0x0419 tx timeout Bluetooth: hci5 command 0x041b tx timeout Bluetooth: hci1 command 0x0405 tx timeout Bluetooth: hci5 command 0x040f tx timeout batman_adv: batadv0: Interface deactivated: batadv_slave_0 batman_adv: batadv0: Removing interface: batadv_slave_0 batman_adv: batadv0: Interface deactivated: batadv_slave_1 batman_adv: batadv0: Removing interface: batadv_slave_1 device bridge_slave_1 left promiscuous mode bridge0: port 2(bridge_slave_1) entered disabled state device bridge_slave_0 left promiscuous mode bridge0: port 1(bridge_slave_0) entered disabled state device veth1_macvtap left promiscuous mode device veth0_macvtap left promiscuous mode device veth1_vlan left promiscuous mode device veth0_vlan left promiscuous mode device hsr_slave_1 left promiscuous mode device hsr_slave_0 left promiscuous mode team0 (unregistering): Port device team_slave_1 removed team0 (unregistering): Port device team_slave_0 removed bond0 (unregistering): Releasing backup interface bond_slave_1 bond0 (unregistering): Releasing backup interface bond_slave_0 bond0 (unregistering): Released all slaves