Warning: Permanently added '10.128.0.52' (ECDSA) to the list of known hosts. syzkaller login: [ 139.305891][ T26] kauditd_printk_skb: 16 callbacks suppressed [ 139.305906][ T26] audit: type=1400 audit(1569191791.142:63): avc: denied { map } for pid=9149 comm="syz-executor456" path="/root/syz-executor456852799" dev="sda1" ino=1426 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 [ 139.419260][ T9150] IPVS: ftp: loaded support on port[0] = 21 [ 139.473937][ T9150] chnl_net:caif_netlink_parms(): no params data found [ 139.501891][ T9150] bridge0: port 1(bridge_slave_0) entered blocking state [ 139.509547][ T9150] bridge0: port 1(bridge_slave_0) entered disabled state [ 139.517989][ T9150] device bridge_slave_0 entered promiscuous mode [ 139.526486][ T9150] bridge0: port 2(bridge_slave_1) entered blocking state [ 139.533565][ T9150] bridge0: port 2(bridge_slave_1) entered disabled state [ 139.541429][ T9150] device bridge_slave_1 entered promiscuous mode [ 139.559443][ T9150] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link [ 139.569907][ T9150] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link [ 139.589208][ T9150] team0: Port device team_slave_0 added [ 139.596244][ T9150] team0: Port device team_slave_1 added [ 139.647989][ T9150] device hsr_slave_0 entered promiscuous mode [ 139.715307][ T9150] device hsr_slave_1 entered promiscuous mode [ 139.773799][ T9150] bridge0: port 2(bridge_slave_1) entered blocking state [ 139.780989][ T9150] bridge0: port 2(bridge_slave_1) entered forwarding state [ 139.788707][ T9150] bridge0: port 1(bridge_slave_0) entered blocking state [ 139.795815][ T9150] bridge0: port 1(bridge_slave_0) entered forwarding state [ 139.830123][ T9150] 8021q: adding VLAN 0 to HW filter on device bond0 [ 139.841290][ T2816] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 139.862541][ T2816] bridge0: port 1(bridge_slave_0) entered disabled state [ 139.870724][ T2816] bridge0: port 2(bridge_slave_1) entered disabled state [ 139.879445][ T2816] IPv6: ADDRCONF(NETDEV_CHANGE): bond0: link becomes ready [ 139.890553][ T9150] 8021q: adding VLAN 0 to HW filter on device team0 [ 139.901222][ T22] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready [ 139.909910][ T22] bridge0: port 1(bridge_slave_0) entered blocking state [ 139.916996][ T22] bridge0: port 1(bridge_slave_0) entered forwarding state [ 139.936479][ T2816] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready [ 139.945054][ T2816] bridge0: port 2(bridge_slave_1) entered blocking state [ 139.952103][ T2816] bridge0: port 2(bridge_slave_1) entered forwarding state [ 139.960341][ T2816] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready [ 139.968946][ T2816] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_1: link becomes ready [ 139.980217][ T9152] IPv6: ADDRCONF(NETDEV_CHANGE): team0: link becomes ready [ 139.988810][ T9152] IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_0: link becomes ready [ 140.000337][ T22] IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready [ 140.010389][ T9150] IPv6: ADDRCONF(NETDEV_CHANGE): hsr0: link becomes ready [ 140.030021][ T9150] 8021q: adding VLAN 0 to HW filter on device batadv0 [ 140.067843][ T26] audit: type=1400 audit(1569191791.902:64): avc: denied { associate } for pid=9150 comm="syz-executor456" name="syz0" scontext=unconfined_u:object_r:unlabeled_t:s0 tcontext=system_u:object_r:unlabeled_t:s0 tclass=filesystem permissive=1 executing program executing program [ 140.177195][ T1524] block nbd0: Receive control failed (result -22) [ 140.184694][ T9159] block nbd0: shutting down sockets [ 140.238915][ T1524] block nbd0: Receive control failed (result -22) [ 140.247949][ T9162] block nbd0: shutting down sockets executing program [ 140.337374][ T1524] block nbd0: Receive control failed (result -22) [ 140.344813][ T9164] block nbd0: shutting down sockets executing program [ 140.426812][ T1524] block nbd0: Receive control failed (result -22) [ 140.434318][ T9166] block nbd0: shutting down sockets executing program executing program [ 140.506605][ T1524] block nbd0: Receive control failed (result -22) [ 140.514050][ T9168] block nbd0: shutting down sockets executing program [ 140.565800][ T1524] block nbd0: Receive control failed (result -22) [ 140.574045][ T9170] block nbd0: shutting down sockets [ 140.636019][ T1524] block nbd0: Receive control failed (result -22) [ 140.643472][ T9172] block nbd0: shutting down sockets executing program [ 140.705544][ T1524] block nbd0: Receive control failed (result -22) [ 140.713588][ T9174] block nbd0: shutting down sockets executing program executing program [ 140.776716][ T1524] block nbd0: Receive control failed (result -22) [ 140.784227][ T9176] block nbd0: shutting down sockets [ 140.837022][ T1524] block nbd0: Receive control failed (result -22) [ 140.844597][ T9178] block nbd0: shutting down sockets executing program [ 140.918014][ T1524] block nbd0: Receive control failed (result -22) [ 140.927025][ T9180] block nbd0: shutting down sockets executing program executing program [ 140.996765][ T1524] block nbd0: Receive control failed (result -22) [ 141.004262][ T9182] block nbd0: shutting down sockets [ 141.056182][ T1524] block nbd0: Receive control failed (result -22) [ 141.064091][ T9184] block nbd0: shutting down sockets executing program [ 141.127037][ T1524] block nbd0: Receive control failed (result -22) [ 141.134645][ T9186] block nbd0: shutting down sockets executing program [ 141.207687][ T1524] block nbd0: Receive control failed (result -22) [ 141.215311][ T9188] block nbd0: shutting down sockets executing program executing program [ 141.276759][ T1524] block nbd0: Receive control failed (result -22) [ 141.284269][ T9190] block nbd0: shutting down sockets [ 141.326873][ T1524] block nbd0: Receive control failed (result -22) [ 141.334399][ T9192] block nbd0: shutting down sockets executing program [ 141.437426][ T1524] block nbd0: Receive control failed (result -22) [ 141.444824][ T9194] block nbd0: shutting down sockets executing program [ 141.508860][ T1524] block nbd0: Receive control failed (result -22) [ 141.516690][ T9196] block nbd0: shutting down sockets executing program [ 141.578482][ T1524] block nbd0: Receive control failed (result -22) [ 141.585931][ T9198] block nbd0: shutting down sockets executing program executing program [ 141.657961][ T1524] block nbd0: Receive control failed (result -22) [ 141.665508][ T9200] block nbd0: shutting down sockets [ 141.716335][ T1524] block nbd0: Receive control failed (result -22) [ 141.723888][ T9202] block nbd0: shutting down sockets executing program [ 141.798115][ T1524] block nbd0: Receive control failed (result -22) [ 141.808921][ T9204] block nbd0: shutting down sockets executing program executing program [ 141.877459][ T1524] block nbd0: Receive control failed (result -22) [ 141.884857][ T9206] block nbd0: shutting down sockets executing program [ 141.937119][ T1524] block nbd0: Receive control failed (result -22) [ 141.944564][ T9208] block nbd0: shutting down sockets [ 141.996979][ T1524] block nbd0: Receive control failed (result -22) [ 142.004660][ T9210] block nbd0: shutting down sockets executing program [ 142.087763][ T1524] block nbd0: Receive control failed (result -22) [ 142.095683][ T1524] block nbd0: shutting down sockets [ 142.101457][ T1524] [ 142.103798][ T1524] ============================================ [ 142.109954][ T1524] WARNING: possible recursive locking detected [ 142.116102][ T1524] 5.3.0+ #0 Not tainted [ 142.120243][ T1524] -------------------------------------------- [ 142.126372][ T1524] kworker/u5:0/1524 is trying to acquire lock: [ 142.132499][ T1524] ffff8880a223e3a8 ((wq_completion)knbd0-recv){+.+.}, at: flush_workqueue+0xf7/0x14b0 [ 142.142032][ T1524] [ 142.142032][ T1524] but task is already holding lock: [ 142.149374][ T1524] ffff8880a223e3a8 ((wq_completion)knbd0-recv){+.+.}, at: process_one_work+0x88b/0x1740 [ 142.159072][ T1524] [ 142.159072][ T1524] other info that might help us debug this: [ 142.167106][ T1524] Possible unsafe locking scenario: [ 142.167106][ T1524] [ 142.174536][ T1524] CPU0 [ 142.177795][ T1524] ---- [ 142.181052][ T1524] lock((wq_completion)knbd0-recv); [ 142.186311][ T1524] lock((wq_completion)knbd0-recv); [ 142.191570][ T1524] [ 142.191570][ T1524] *** DEADLOCK *** [ 142.191570][ T1524] [ 142.199703][ T1524] May be due to missing lock nesting notation [ 142.199703][ T1524] [ 142.208006][ T1524] 3 locks held by kworker/u5:0/1524: [ 142.213262][ T1524] #0: ffff8880a223e3a8 ((wq_completion)knbd0-recv){+.+.}, at: process_one_work+0x88b/0x1740 [ 142.223406][ T1524] #1: ffff8880a619fdc0 ((work_completion)(&args->work)){+.+.}, at: process_one_work+0x8c1/0x1740 [ 142.233972][ T1524] #2: ffff888219398438 (&nbd->config_lock){+.+.}, at: refcount_dec_and_mutex_lock+0x56/0x90 [ 142.244108][ T1524] [ 142.244108][ T1524] stack backtrace: [ 142.249982][ T1524] CPU: 0 PID: 1524 Comm: kworker/u5:0 Not tainted 5.3.0+ #0 [ 142.257236][ T1524] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 142.267363][ T1524] Workqueue: knbd0-recv recv_work [ 142.272361][ T1524] Call Trace: [ 142.275648][ T1524] dump_stack+0x172/0x1f0 [ 142.279969][ T1524] __lock_acquire.cold+0x188/0x398 [ 142.285153][ T1524] ? mark_held_locks+0xf0/0xf0 [ 142.289897][ T1524] lock_acquire+0x190/0x410 [ 142.294380][ T1524] ? flush_workqueue+0xf7/0x14b0 [ 142.299311][ T1524] flush_workqueue+0x126/0x14b0 [ 142.304137][ T1524] ? flush_workqueue+0xf7/0x14b0 [ 142.309053][ T1524] ? lock_downgrade+0x920/0x920 [ 142.313882][ T1524] ? drain_workqueue+0x2b/0x470 [ 142.318720][ T1524] ? debug_check_no_obj_freed+0x20a/0x43f [ 142.324420][ T1524] ? find_held_lock+0x35/0x130 [ 142.329162][ T1524] ? pwq_unbound_release_workfn+0x2f0/0x2f0 [ 142.335050][ T1524] ? mark_lock+0xc2/0x1220 [ 142.339445][ T1524] drain_workqueue+0x1b4/0x470 [ 142.344185][ T1524] ? drain_workqueue+0x1b4/0x470 [ 142.349099][ T1524] ? kfree+0x226/0x2c0 [ 142.353176][ T1524] destroy_workqueue+0x21/0x6c0 [ 142.358006][ T1524] ? nbd_config_put+0x378/0x870 [ 142.362834][ T1524] nbd_config_put+0x3dd/0x870 [ 142.367491][ T1524] recv_work+0x19b/0x200 [ 142.371712][ T1524] process_one_work+0x9af/0x1740 [ 142.376630][ T1524] ? pwq_dec_nr_in_flight+0x320/0x320 [ 142.382001][ T1524] ? lock_acquire+0x190/0x410 executing program [ 142.386659][ T1524] worker_thread+0x98/0xe40 [ 142.391163][ T1524] kthread+0x361/0x430 [ 142.395234][ T1524] ? process_one_work+0x1740/0x1740 [ 142.400414][ T1524] ? kthread_cancel_delayed_work_sync+0x20/0x20 [ 142.406644][ T1524] ret_from_fork+0x24/0x30