executing program syzkaller login: [ 615.391845] INFO: task syzkaller741492:3041 blocked for more than 120 seconds. [ 615.394009] Not tainted 4.13.0-rc6-next-20170825+ #9 [ 615.397175] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 615.399366] syzkaller741492 D23824 3041 3039 0x00000000 [ 615.401491] Call Trace: [ 615.402548] __schedule+0x8e8/0x2070 [ 615.404007] ? __sched_text_start+0x8/0x8 [ 615.405575] ? prepare_to_wait_exclusive+0xb6/0x530 [ 615.407274] ? find_held_lock+0x39/0x1d0 [ 615.408692] ? trace_hardirqs_on_caller+0x19e/0x5c0 [ 615.410371] ? trace_hardirqs_on+0xd/0x10 [ 615.411782] schedule+0x108/0x440 [ 615.413008] ? __schedule+0x2070/0x2070 [ 615.414433] ? mark_held_locks+0xb2/0x100 [ 615.420117] ? __local_bh_enable_ip+0x9d/0x160 [ 615.421678] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 615.422978] ? __lock_sock+0x1d7/0x2f0 [ 615.424012] ? trace_hardirqs_on+0xd/0x10 [ 615.425169] ? __local_bh_enable_ip+0x9d/0x160 [ 615.426398] __lock_sock+0x1dc/0x2f0 [ 615.427400] ? proto_unregister+0x5e0/0x5e0 [ 615.428569] ? finish_wait+0x490/0x490 [ 615.429932] ? lock_sock_nested+0x44/0x110 [ 615.431404] lock_sock_nested+0xf3/0x110 [ 615.432806] tcp_sendmsg+0x21/0x50 [ 615.434091] inet_sendmsg+0x11f/0x5e0 [ 615.435385] ? inet_recvmsg+0x5f0/0x5f0 [ 615.436766] ? selinux_socket_sendmsg+0x36/0x40 [ 615.438988] ? security_socket_sendmsg+0x89/0xb0 [ 615.439874] ? inet_recvmsg+0x5f0/0x5f0 [ 615.440642] sock_sendmsg+0xca/0x110 [ 615.441357] kernel_sendmsg+0x47/0x60 [ 615.442096] sock_no_sendpage+0x1cc/0x280 [ 615.442827] ? sock_no_shutdown+0x10/0x10 [ 615.443642] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 615.444369] tcp_sendpage_locked+0x10b/0x160 [ 615.444974] tcp_sendpage+0x43/0x60 [ 615.445517] ? tcp_sendpage_locked+0x160/0x160 [ 615.446180] inet_sendpage+0x1aa/0x660 [ 615.446718] ? inet_sendmsg+0x5e0/0x5e0 [ 615.447307] ? inet_sendmsg+0x5e0/0x5e0 [ 615.447852] kernel_sendpage+0x8d/0xe0 [ 615.448443] sock_sendpage+0x92/0xc0 [ 615.448860] ? kernel_sendpage+0xe0/0xe0 [ 615.449345] pipe_to_sendpage+0x290/0x3b0 [ 615.449809] ? direct_splice_actor+0x180/0x180 [ 615.450349] ? check_same_owner+0x320/0x320 [ 615.450840] ? splice_from_pipe_next.part.9+0x22a/0x2e0 [ 615.451469] __splice_from_pipe+0x343/0x750 [ 615.451956] ? direct_splice_actor+0x180/0x180 [ 615.452508] splice_from_pipe+0x1e9/0x330 [ 615.452969] ? direct_splice_actor+0x180/0x180 [ 615.453500] ? splice_shrink_spd+0xb0/0xb0 [ 615.453907] ? security_file_permission+0x89/0x1f0 [ 615.454402] generic_splice_sendpage+0x40/0x50 [ 615.454829] ? splice_from_pipe+0x330/0x330 [ 615.455262] SyS_splice+0x7d5/0x1630 [ 615.455616] ? do_writev+0xfc/0x2a0 [ 615.455972] ? compat_SyS_vmsplice+0x250/0x250 [ 615.456426] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 615.456893] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 615.457371] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 615.457814] RIP: 0033:0x434f29 [ 615.458749] RSP: 002b:00007ffdbde9e948 EFLAGS: 00000203 ORIG_RAX: 0000000000000113 [ 615.459388] RAX: ffffffffffffffda RBX: 00000000004002b0 RCX: 0000000000434f29 [ 615.459971] RDX: 0000000000000005 RSI: 0000000000000000 RDI: 0000000000000003 [ 615.460580] RBP: 0000000000000086 R08: 0000000000000009 R09: 0000000000000004 [ 615.461170] R10: 0000000000000000 R11: 0000000000000203 R12: 0000000000000000 [ 615.461736] R13: 00000000004018a0 R14: 0000000000401930 R15: 0000000000000000 [ 615.462353] [ 615.462353] Showing all locks held in the system: [ 615.462861] 2 locks held by khungtaskd/663: [ 615.463242] #0: (rcu_read_lock){....}, at: [] watchdog+0x1c5/0xd60 [ 615.463854] #1: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0xd2/0x410 [ 615.464528] 1 lock held by rsyslogd/2927: [ 615.464821] #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0x131/0x1a0 [ 615.465442] 2 locks held by getty/3010: [ 615.465723] #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 [ 615.466361] #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a40 [ 615.467040] 2 locks held by getty/3011: [ 615.467318] #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 [ 615.467937] #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a40 [ 615.468617] 2 locks held by getty/3012: [ 615.468875] #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 [ 615.469460] #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a40 [ 615.470084] 2 locks held by getty/3013: [ 615.470341] #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 [ 615.470933] #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a40 [ 615.471592] 2 locks held by getty/3014: [ 615.471883] #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 [ 615.472456] #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a40 [ 615.473091] 2 locks held by getty/3015: [ 615.473340] #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 [ 615.473889] #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a40 [ 615.474498] 2 locks held by getty/3016: [ 615.474792] #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 [ 615.475360] #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a40 [ 615.475950] 2 locks held by syzkaller741492/3041: [ 615.476272] #0: (&pipe->mutex/1){+.+.}, at: [] pipe_lock+0x56/0x70 [ 615.476818] #1: (sk_lock-AF_INET){+.+.}, at: [] tcp_sendpage+0x2e/0x60 [ 615.477373] [ 615.477483] ============================================= [ 615.477483] [ 615.477945] NMI backtrace for cpu 0 [ 615.478198] CPU: 0 PID: 663 Comm: khungtaskd Not tainted 4.13.0-rc6-next-20170825+ #9 [ 615.478688] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 [ 615.479798] Call Trace: [ 615.480002] dump_stack+0x194/0x257 [ 615.480279] ? arch_local_irq_restore+0x53/0x53 [ 615.480609] nmi_cpu_backtrace+0x20e/0x240 [ 615.480905] ? kobject_synth_uevent+0xad0/0xad0 [ 615.481239] ? debug_check_no_locks_held+0x140/0x140 [ 615.481601] ? show_regs_print_info+0x65/0x65 [ 615.481916] ? irq_force_complete_move+0x390/0x390 [ 615.482267] nmi_trigger_cpumask_backtrace+0x122/0x180 [ 615.482626] arch_trigger_cpumask_backtrace+0x14/0x20 [ 615.482978] watchdog+0x90c/0xd60 [ 615.483247] ? reset_hung_task_detector+0xa0/0xa0 [ 615.483564] ? complete+0x18/0x80 [ 615.483816] ? __schedule+0x2070/0x2070 [ 615.484118] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 615.484453] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 615.484794] ? trace_hardirqs_on+0xd/0x10 [ 615.485080] ? __kthread_parkme+0x173/0x240 [ 615.485383] kthread+0x39c/0x470 [ 615.485594] ? reset_hung_task_detector+0xa0/0xa0 [ 615.485894] ? kthread_create_on_node+0x100/0x100 [ 615.486199] ret_from_fork+0x2a/0x40 [ 615.486486] Sending NMI from CPU 0 to CPUs 1-3: [ 615.486970] NMI backtrace for cpu 2 [ 615.486974] CPU: 2 PID: 2925 Comm: rs:main Q:Reg Not tainted 4.13.0-rc6-next-20170825+ #9 [ 615.486976] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 [ 615.486978] task: ffff880068ffc340 task.stack: ffff8800697d0000 [ 615.486998] RIP: 0010:memcmp+0xcb/0x160 [ 615.487000] RSP: 0018:ffff8800697d6ba0 EFLAGS: 00000246 [ 615.487005] RAX: 0000000000000000 RBX: ffff8800697d6ce0 RCX: 00000000000000ff [ 615.487021] RDX: ffff8800697d6ce0 RSI: ffff880068d165b0 RDI: 0000000000000007 [ 615.487023] RBP: ffff8800697d6bc8 R08: 0000000000000000 R09: 1ffff1000d2fad42 [ 615.487026] R10: 00000000db37e248 R11: 00000000bc08ac0a R12: dffffc0000000000 [ 615.487028] R13: 0000000000000098 R14: ffff880068d16500 R15: ffff8800697d6c48 [ 615.487045] FS: 00007f9212fab700(0000) GS:ffff88006de00000(0000) knlGS:0000000000000000 [ 615.487047] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 615.487050] CR2: 000055d48e77de50 CR3: 0000000038f43000 CR4: 00000000000006e0 [ 615.487054] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 615.487056] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 615.487057] Call Trace: [ 615.487063] depot_save_stack+0x12c/0x490 [ 615.487069] save_stack+0xa3/0xd0 [ 615.487073] ? save_stack_trace+0x16/0x20 [ 615.487076] ? save_stack+0x43/0xd0 [ 615.487080] ? kasan_kmalloc+0xad/0xe0 [ 615.487082] ? kasan_slab_alloc+0x12/0x20 [ 615.487086] ? kmem_cache_alloc+0x11b/0x760 [ 615.487089] ? alloc_buffer_head+0x76/0x190 [ 615.487092] ? alloc_page_buffers+0xb7/0x200 [ 615.487096] ? create_empty_buffers+0xd0/0x7b0 [ 615.487099] ? create_page_buffers+0x1ed/0x290 [ 615.487102] ? __block_write_begin_int+0x22c/0x1410 [ 615.487106] ? __block_write_begin+0x30/0x40 [ 615.487110] ? ext4_da_write_begin+0x4f1/0x1020 [ 615.487113] ? generic_perform_write+0x28c/0x650 [ 615.487116] ? __generic_file_write_iter+0x366/0x5b0 [ 615.487119] ? ext4_file_write_iter+0x59e/0x10b0 [ 615.487123] ? __vfs_write+0x68a/0x970 [ 615.487126] ? vfs_write+0x18f/0x510 [ 615.487129] ? SyS_write+0xef/0x220 [ 615.487133] ? entry_SYSCALL_64_fastpath+0x1f/0xbe [ 615.487139] ? __lock_is_held+0xbc/0x140 [ 615.487146] ? check_same_owner+0x320/0x320 [ 615.487150] ? check_noncircular+0x20/0x20 [ 615.487155] ? kasan_unpoison_shadow+0x35/0x50 [ 615.487158] kasan_kmalloc+0xad/0xe0 [ 615.487163] kasan_slab_alloc+0x12/0x20 [ 615.487166] kmem_cache_alloc+0x11b/0x760 [ 615.487172] alloc_buffer_head+0x76/0x190 [ 615.487176] ? recalc_bh_state.part.34+0x150/0x150 [ 615.487181] ? lock_downgrade+0x990/0x990 [ 615.487186] alloc_page_buffers+0xb7/0x200 [ 615.487191] create_empty_buffers+0xd0/0x7b0 [ 615.487196] ? lock_release+0xd70/0xd70 [ 615.487200] ? attach_nobh_buffers+0x560/0x560 [ 615.487204] ? save_stack_trace+0x16/0x20 [ 615.487210] ? start_this_handle+0x4b8/0x1080 [ 615.487214] ? start_this_handle+0x597/0x1080 [ 615.487217] ? vfs_write+0x18f/0x510 [ 615.487220] ? SyS_write+0xef/0x220 [ 615.487226] ? jbd2_journal_free_reserved+0xf0/0xf0 [ 615.487229] ? check_noncircular+0x20/0x20 [ 615.487232] ? alloc_pages_current+0xbe/0x1e0 [ 615.487236] ? __lock_is_held+0xbc/0x140 [ 615.487239] ? __page_cache_alloc+0x165/0x4d0 [ 615.487245] create_page_buffers+0x1ed/0x290 [ 615.487250] ? create_empty_buffers+0x7b0/0x7b0 [ 615.487254] ? __lock_is_held+0xbc/0x140 [ 615.487259] __block_write_begin_int+0x22c/0x1410 [ 615.487263] ? __lock_is_held+0xbc/0x140 [ 615.487281] ? check_noncircular+0x20/0x20 [ 615.487285] ? ext4_inode_attach_jinode.part.67+0x150/0x150 [ 615.487290] ? __breadahead+0x150/0x150 [ 615.487295] ? jbd2_write_access_granted.part.9+0x3a0/0x3a0 [ 615.487299] ? rcu_note_context_switch+0x710/0x710 [ 615.487303] ? __lock_is_held+0xbc/0x140 [ 615.487307] ? __lock_is_held+0xbc/0x140 [ 615.487313] ? __ext4_journal_start_sb+0x167/0x550 [ 615.487318] ? check_same_owner+0x320/0x320 [ 615.487322] ? wb_domain_writeout_inc.part.27+0xa0/0xa0 [ 615.487325] ? wait_for_stable_page+0x173/0x310 [ 615.487329] ? wb_domain_writeout_inc.part.27+0xa0/0xa0 [ 615.487333] ? ext4_inode_attach_jinode.part.67+0x150/0x150 [ 615.487337] __block_write_begin+0x30/0x40 [ 615.487341] ext4_da_write_begin+0x4f1/0x1020 [ 615.487348] ? ext4_write_begin+0x1400/0x1400 [ 615.487353] ? __test_set_page_writeback+0x1210/0x1210 [ 615.487356] ? generic_write_end+0x2c3/0x460 [ 615.487361] ? block_write_end+0x1c0/0x1c0 [ 615.487365] ? check_noncircular+0x20/0x20 [ 615.487368] ? __lock_is_held+0xbc/0x140 [ 615.487386] ? __ext4_journal_stop+0x76/0x1c0 [ 615.487390] ? ext4_da_write_end+0x4b6/0xaf0 [ 615.487396] ? iov_iter_advance+0x2a1/0x13f0 [ 615.487399] ? __lock_is_held+0xbc/0x140 [ 615.487402] ? ext4_write_end+0xe90/0xe90 [ 615.487406] ? iov_iter_fault_in_readable+0x20e/0x410 [ 615.487410] ? iov_iter_revert+0x9d0/0x9d0 [ 615.487415] ? iov_iter_copy_from_user_atomic+0xd30/0xd30 [ 615.487418] ? check_same_owner+0x320/0x320 [ 615.487422] ? current_kernel_time64+0x122/0x2f0 [ 615.487427] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 615.487431] generic_perform_write+0x28c/0x650 [ 615.487438] ? add_page_wait_queue+0x290/0x290 [ 615.487441] ? current_time+0x88/0xc0 [ 615.487445] ? file_update_time+0xbf/0x470 [ 615.487449] ? current_time+0xc0/0xc0 [ 615.487453] ? generic_write_checks+0x2f2/0x540 [ 615.487458] __generic_file_write_iter+0x366/0x5b0 [ 615.487461] ? mutex_lock_io_nested+0x1740/0x1740 [ 615.487466] ext4_file_write_iter+0x59e/0x10b0 [ 615.487469] ? __lock_is_held+0xbc/0x140 [ 615.487474] ? ext4_file_mmap+0x1b0/0x1b0 [ 615.487478] ? __fget+0x362/0x580 [ 615.487481] ? lock_downgrade+0x990/0x990 [ 615.487486] ? check_noncircular+0x20/0x20 [ 615.487489] ? iterate_fd+0x3f0/0x3f0 [ 615.487494] ? __lock_is_held+0xbc/0x140 [ 615.487499] ? check_noncircular+0x20/0x20 [ 615.487503] ? iov_iter_init+0xaf/0x1d0 [ 615.487508] __vfs_write+0x68a/0x970 [ 615.487512] ? default_llseek+0x2a0/0x2a0 [ 615.487521] ? rcu_sync_lockdep_assert+0x6d/0xb0 [ 615.487525] ? __sb_start_write+0x203/0x290 [ 615.487529] vfs_write+0x18f/0x510 [ 615.487534] SyS_write+0xef/0x220 [ 615.487539] ? SyS_read+0x220/0x220 [ 615.487542] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 615.487546] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 615.487551] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 615.487554] RIP: 0033:0x7f9214a0919d [ 615.487555] RSP: 002b:00007f9212faa000 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 [ 615.487559] RAX: ffffffffffffffda RBX: 00000000000003d2 RCX: 00007f9214a0919d [ 615.487561] RDX: 00000000000003d2 RSI: 00000000012ee340 RDI: 0000000000000006 [ 615.487563] RBP: 0000000000000086 R08: 0a3a332d31207355 R09: 676e69646e655320 [ 615.487565] R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001 [ 615.487566] R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000 [ 615.487571] Code: b6 03 48 c1 e9 03 83 e7 07 42 0f b6 0c 21 40 38 f9 7f 04 84 c9 75 7c 0f b6 0e 29 c8 75 0f 48 83 c3 01 48 83 c6 01 48 39 d3 75 b4 <31> c0 48 83 c4 18 5b 41 5c 5d c3 48 89 55 e0 48 89 75 e8 e8 ed [ 615.487626] NMI backtrace for cpu 1 skipped: idling at pc 0xffffffff84da2b86 [ 615.487630] NMI backtrace for cpu 3 skipped: idling at pc 0xffffffff84da2b86 [ 615.487982] Kernel panic - not syncing: hung_task: blocked tasks [ 615.487989] CPU: 0 PID: 663 Comm: khungtaskd Not tainted 4.13.0-rc6-next-20170825+ #9 [ 615.487993] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 [ 615.487996] Call Trace: [ 615.488006] dump_stack+0x194/0x257 [ 615.488017] ? arch_local_irq_restore+0x53/0x53 [ 615.488038] panic+0x1e4/0x41c [ 615.488046] ? refcount_error_report+0x214/0x214 [ 615.488073] watchdog+0x91d/0xd60 [ 615.488094] ? reset_hung_task_detector+0xa0/0xa0 [ 615.488101] ? complete+0x18/0x80 [ 615.488118] ? __schedule+0x2070/0x2070 [ 615.488136] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 615.488146] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 615.488155] ? trace_hardirqs_on+0xd/0x10 [ 615.488162] ? __kthread_parkme+0x173/0x240 [ 615.488175] kthread+0x39c/0x470 [ 615.488182] ? reset_hung_task_detector+0xa0/0xa0 [ 615.488188] ? kthread_create_on_node+0x100/0x100 [ 615.488200] ret_from_fork+0x2a/0x40 [ 615.551565] Dumping ftrace buffer: [ 615.551849] (ftrace buffer empty) [ 615.552089] Kernel Offset: disabled [ 615.552325] Rebooting in 86400 seconds..