Warning: Permanently added '10.128.0.165' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 61.996576][ T6834] IPVS: ftp: loaded support on port[0] = 21 [ 62.051573][ T6834] IPVS: ftp: loaded support on port[0] = 21 [ 62.107732][ T7] tipc: TX() has been purged, node left! [ 62.144818][ T6834] [ 62.147173][ T6834] ====================================================== [ 62.154177][ T6834] WARNING: possible circular locking dependency detected [ 62.161180][ T6834] 5.9.0-rc2-next-20200828-syzkaller #0 Not tainted [ 62.167660][ T6834] ------------------------------------------------------ [ 62.174685][ T6834] syz-executor348/6834 is trying to acquire lock: [ 62.181118][ T6834] ffffffff8a879430 (pernet_ops_rwsem){++++}-{3:3}, at: unregister_netdevice_notifier+0x1e/0x170 [ 62.191589][ T6834] [ 62.191589][ T6834] but task is already holding lock: [ 62.198946][ T6834] ffff88809d732210 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: __sock_release+0x86/0x280 [ 62.209041][ T6834] [ 62.209041][ T6834] which lock already depends on the new lock. [ 62.209041][ T6834] [ 62.219437][ T6834] [ 62.219437][ T6834] the existing dependency chain (in reverse order) is: [ 62.228454][ T6834] [ 62.228454][ T6834] -> #3 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}: [ 62.237155][ T6834] down_write+0x8d/0x150 [ 62.241939][ T6834] __sock_release+0x86/0x280 [ 62.247051][ T6834] sock_close+0x18/0x20 [ 62.251718][ T6834] __fput+0x285/0x920 [ 62.256209][ T6834] delayed_fput+0x56/0x70 [ 62.261050][ T6834] process_one_work+0x94c/0x1670 [ 62.266496][ T6834] worker_thread+0x64c/0x1120 [ 62.271681][ T6834] kthread+0x3b5/0x4a0 [ 62.276270][ T6834] ret_from_fork+0x1f/0x30 [ 62.281185][ T6834] [ 62.281185][ T6834] -> #2 ((delayed_fput_work).work){+.+.}-{0:0}: [ 62.289609][ T6834] process_one_work+0x8bb/0x1670 [ 62.295056][ T6834] worker_thread+0x64c/0x1120 [ 62.300240][ T6834] kthread+0x3b5/0x4a0 [ 62.304820][ T6834] ret_from_fork+0x1f/0x30 [ 62.310256][ T6834] [ 62.310256][ T6834] -> #1 ((wq_completion)events){+.+.}-{0:0}: [ 62.318416][ T6834] flush_workqueue+0x110/0x13e0 [ 62.323777][ T6834] tipc_exit_net+0x47/0x2a0 [ 62.328893][ T6834] ops_exit_list+0xb0/0x160 [ 62.333919][ T6834] cleanup_net+0x4ea/0xb10 [ 62.338844][ T6834] process_one_work+0x94c/0x1670 [ 62.344289][ T6834] worker_thread+0x64c/0x1120 [ 62.349472][ T6834] kthread+0x3b5/0x4a0 [ 62.354051][ T6834] ret_from_fork+0x1f/0x30 [ 62.358967][ T6834] [ 62.358967][ T6834] -> #0 (pernet_ops_rwsem){++++}-{3:3}: [ 62.366698][ T6834] __lock_acquire+0x2a6b/0x5640 [ 62.372057][ T6834] lock_acquire+0x1f1/0xad0 [ 62.377078][ T6834] down_write+0x8d/0x150 [ 62.381845][ T6834] unregister_netdevice_notifier+0x1e/0x170 [ 62.388270][ T6834] bcm_release+0x94/0x750 [ 62.393152][ T6834] __sock_release+0xcd/0x280 [ 62.398279][ T6834] sock_close+0x18/0x20 [ 62.402956][ T6834] __fput+0x285/0x920 [ 62.407460][ T6834] task_work_run+0xdd/0x190 [ 62.412485][ T6834] do_exit+0xb7d/0x29f0 [ 62.417159][ T6834] do_group_exit+0x125/0x310 [ 62.422268][ T6834] __x64_sys_exit_group+0x3a/0x50 [ 62.427826][ T6834] do_syscall_64+0x2d/0x70 [ 62.432759][ T6834] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 62.439169][ T6834] [ 62.439169][ T6834] other info that might help us debug this: [ 62.439169][ T6834] [ 62.449407][ T6834] Chain exists of: [ 62.449407][ T6834] pernet_ops_rwsem --> (delayed_fput_work).work --> &sb->s_type->i_mutex_key#13 [ 62.449407][ T6834] [ 62.464356][ T6834] Possible unsafe locking scenario: [ 62.464356][ T6834] [ 62.471796][ T6834] CPU0 CPU1 [ 62.477144][ T6834] ---- ---- [ 62.482490][ T6834] lock(&sb->s_type->i_mutex_key#13); [ 62.487940][ T6834] lock((delayed_fput_work).work); [ 62.495641][ T6834] lock(&sb->s_type->i_mutex_key#13); [ 62.503620][ T6834] lock(pernet_ops_rwsem); [ 62.508111][ T6834] [ 62.508111][ T6834] *** DEADLOCK *** [ 62.508111][ T6834] [ 62.516246][ T6834] 1 lock held by syz-executor348/6834: [ 62.521697][ T6834] #0: ffff88809d732210 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: __sock_release+0x86/0x280 [ 62.532215][ T6834] [ 62.532215][ T6834] stack backtrace: [ 62.538099][ T6834] CPU: 1 PID: 6834 Comm: syz-executor348 Not tainted 5.9.0-rc2-next-20200828-syzkaller #0 [ 62.547968][ T6834] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 62.558005][ T6834] Call Trace: [ 62.561295][ T6834] dump_stack+0x18f/0x20d [ 62.565620][ T6834] check_noncircular+0x324/0x3e0 [ 62.570551][ T6834] ? print_circular_bug+0x3a0/0x3a0 [ 62.575767][ T6834] ? lock_repin_lock+0x460/0x460 [ 62.580692][ T6834] ? mark_lock+0xbc/0x1710 [ 62.585098][ T6834] ? unwind_next_frame+0xe3b/0x1f90 [ 62.590289][ T6834] __lock_acquire+0x2a6b/0x5640 [ 62.595136][ T6834] ? lockdep_hardirqs_on_prepare+0x530/0x530 [ 62.601105][ T6834] ? __lock_acquire+0x16cb/0x5640 [ 62.606131][ T6834] lock_acquire+0x1f1/0xad0 [ 62.610637][ T6834] ? unregister_netdevice_notifier+0x1e/0x170 [ 62.616707][ T6834] ? lock_release+0x8e0/0x8e0 [ 62.621383][ T6834] ? lock_is_held_type+0xbb/0xf0 [ 62.626316][ T6834] down_write+0x8d/0x150 [ 62.630564][ T6834] ? unregister_netdevice_notifier+0x1e/0x170 [ 62.636623][ T6834] ? down_write_killable+0x170/0x170 [ 62.641914][ T6834] ? _raw_spin_unlock_irqrestore+0x62/0xe0 [ 62.647751][ T6834] ? lock_is_held_type+0xbb/0xf0 [ 62.652697][ T6834] unregister_netdevice_notifier+0x1e/0x170 [ 62.658598][ T6834] bcm_release+0x94/0x750 [ 62.662924][ T6834] ? locks_remove_file+0x319/0x580 [ 62.668040][ T6834] ? fcntl_setlk+0xf60/0xf60 [ 62.672661][ T6834] __sock_release+0xcd/0x280 [ 62.677278][ T6834] sock_close+0x18/0x20 [ 62.681437][ T6834] __fput+0x285/0x920 [ 62.685424][ T6834] ? __sock_release+0x280/0x280 [ 62.690284][ T6834] task_work_run+0xdd/0x190 [ 62.694792][ T6834] do_exit+0xb7d/0x29f0 [ 62.698952][ T6834] ? mm_update_next_owner+0x7a0/0x7a0 [ 62.704343][ T6834] ? lock_is_held_type+0xbb/0xf0 [ 62.709286][ T6834] do_group_exit+0x125/0x310 [ 62.713887][ T6834] __x64_sys_exit_group+0x3a/0x50 [ 62.718932][ T6834] do_syscall_64+0x2d/0x70 [ 62.723356][ T6834] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 62.729253][ T6834] RIP: 0033:0x4400d8 [ 62.733130][ T6834] Code: Bad RIP value. [ 62.737200][ T6834] RSP: 002b:00007fffe707b108 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 62.745618][ T6834] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00000000004400d8 [ 62.753594][ T6834] RDX: 0000000000000001 RSI: 000000000000003c RDI: 0000000000000001 [ 62.761553][ T6834] RBP: 00000000004c63d0 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 62.769511][ T6834] R10: 00000000bb1414ac R11: 0000000000000246 R12: 0000000000000001 [ 62.777485][ T6834] R13: 00000000006d85e0 R14: 0000000000000000 R15: 0000000000000000