INFO: task syz-executor.5:2123 blocked for more than 140 seconds. Not tainted 4.9.177+ #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28056 2123 2074 0x00000004 ffff8801cfc617c0 0000000000000000 ffff8801db721000 ffff8801c5f02f80 ffff8801db721018 ffff8801c435f680 ffffffff82808bde 0000000000000246 ffff8801cfc617c0 0000000000000000 ffff8801db7218f0 1ffff1003886bebf Call Trace: [<0000000029e0b335>] schedule+0x92/0x1c0 kernel/sched/core.c:3546 [<0000000010eaf8a8>] __rt_mutex_slowlock+0x99/0x290 kernel/locking/rtmutex.c:1221 [<00000000a5175a44>] rt_mutex_slowlock+0x199/0x4c0 kernel/locking/rtmutex.c:1293 [<00000000e04f670c>] rt_mutex_fastlock kernel/locking/rtmutex.c:1439 [inline] [<00000000e04f670c>] rt_mutex_lock+0x2d/0x40 kernel/locking/rtmutex.c:1499 [<000000005a8e54d5>] process_notifier drivers/misc/uid_sys_stats.c:636 [inline] [<000000005a8e54d5>] process_notifier+0x96/0x670 drivers/misc/uid_sys_stats.c:625 [<000000003b525456>] notifier_call_chain+0xb4/0x1d0 kernel/notifier.c:93 [<000000009f9fe7ef>] __blocking_notifier_call_chain kernel/notifier.c:317 [inline] [<000000009f9fe7ef>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] [<000000009f9fe7ef>] blocking_notifier_call_chain kernel/notifier.c:328 [inline] [<000000009f9fe7ef>] blocking_notifier_call_chain+0x80/0xa0 kernel/notifier.c:325 [<000000002ac93787>] profile_task_exit+0x1f/0x30 kernel/profile.c:140 [<000000003c258174>] do_exit+0x90/0x2aa0 kernel/exit.c:744 [<0000000038a60393>] do_group_exit+0x111/0x300 kernel/exit.c:945 [<00000000ff0995ff>] get_signal+0x348/0x1aa0 kernel/signal.c:2380 [<000000009cca9d92>] do_signal+0x9c/0x1920 arch/x86/kernel/signal.c:807 [<00000000d8d89aa8>] exit_to_usermode_loop+0x11c/0x160 arch/x86/entry/common.c:159 [<00000000cc143f0d>] prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] [<00000000cc143f0d>] syscall_return_slowpath arch/x86/entry/common.c:266 [inline] [<00000000cc143f0d>] do_syscall_64+0x3ab/0x5c0 arch/x86/entry/common.c:293 [<0000000002beb36d>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb Showing all locks held in the system: 2 locks held by khungtaskd/24: #0: (rcu_read_lock){......}, at: [<000000008a804b38>] check_hung_uninterruptible_tasks kernel/hung_task.c:169 [inline] #0: (rcu_read_lock){......}, at: [<000000008a804b38>] watchdog+0x14b/0xaf0 kernel/hung_task.c:263 #1: (tasklist_lock){.+.+..}, at: [<0000000030f293ba>] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4336 4 locks held by rs:main Q:Reg/1912: #0: (&f->f_pos_lock){+.+.+.}, at: [<000000006b60ffee>] __fdget_pos+0xa8/0xd0 fs/file.c:782 #1: (sb_writers#4){.+.+.+}, at: [<0000000080e7b4ef>] file_start_write include/linux/fs.h:2643 [inline] #1: (sb_writers#4){.+.+.+}, at: [<0000000080e7b4ef>] vfs_write+0x3e9/0x520 fs/read_write.c:558 #2: (&sbi->s_journal_flag_rwsem){.+.+.+}, at: [<00000000496d0242>] do_writepages+0xfc/0x1e0 mm/page-writeback.c:2338 #3: (&ei->i_data_sem){++++..}, at: [<000000003993f088>] ext4_map_blocks+0x754/0x16d0 fs/ext4/inode.c:605 1 lock held by rsyslogd/1914: #0: (&f->f_pos_lock){+.+.+.}, at: [<000000006b60ffee>] __fdget_pos+0xa8/0xd0 fs/file.c:782 2 locks held by getty/2042: #0: (&tty->ldisc_sem){++++++}, at: [<00000000be40d49f>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+...}, at: [<0000000037d24fb9>] n_tty_read+0x1fe/0x1820 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.5/2123: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain kernel/notifier.c:328 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain+0x6a/0xa0 kernel/notifier.c:325 1 lock held by syz-executor.0/2124: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain kernel/notifier.c:328 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain+0x6a/0xa0 kernel/notifier.c:325 1 lock held by syz-executor.3/2126: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain kernel/notifier.c:328 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain+0x6a/0xa0 kernel/notifier.c:325 1 lock held by udevd/3119: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain kernel/notifier.c:328 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain+0x6a/0xa0 kernel/notifier.c:325 1 lock held by kworker/dying/5335: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain kernel/notifier.c:328 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain+0x6a/0xa0 kernel/notifier.c:325 1 lock held by kworker/dying/10031: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain kernel/notifier.c:328 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain+0x6a/0xa0 kernel/notifier.c:325 1 lock held by kworker/dying/15092: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain kernel/notifier.c:328 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain+0x6a/0xa0 kernel/notifier.c:325 1 lock held by kworker/dying/15103: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain kernel/notifier.c:328 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain+0x6a/0xa0 kernel/notifier.c:325 1 lock held by kworker/dying/28921: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain kernel/notifier.c:328 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain+0x6a/0xa0 kernel/notifier.c:325 1 lock held by syz-executor.4/28960: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain kernel/notifier.c:328 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain+0x6a/0xa0 kernel/notifier.c:325 1 lock held by kworker/dying/28977: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain kernel/notifier.c:328 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain+0x6a/0xa0 kernel/notifier.c:325 1 lock held by syz-executor.2/29460: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain kernel/notifier.c:328 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain+0x6a/0xa0 kernel/notifier.c:325 1 lock held by syz-executor.1/29466: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain kernel/notifier.c:328 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain+0x6a/0xa0 kernel/notifier.c:325 1 lock held by syz-executor.0/1501: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain kernel/notifier.c:328 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain+0x6a/0xa0 kernel/notifier.c:325 1 lock held by syz-executor.0/1504: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain kernel/notifier.c:328 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain+0x6a/0xa0 kernel/notifier.c:325 1 lock held by syz-executor.0/1547: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain kernel/notifier.c:328 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain+0x6a/0xa0 kernel/notifier.c:325 1 lock held by syz-executor.0/1548: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain kernel/notifier.c:328 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain+0x6a/0xa0 kernel/notifier.c:325 1 lock held by syz-executor.3/1505: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain kernel/notifier.c:328 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain+0x6a/0xa0 kernel/notifier.c:325 1 lock held by syz-executor.3/1511: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain kernel/notifier.c:328 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain+0x6a/0xa0 kernel/notifier.c:325 1 lock held by syz-executor.5/1528: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain kernel/notifier.c:328 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain+0x6a/0xa0 kernel/notifier.c:325 1 lock held by syz-executor.5/1529: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain kernel/notifier.c:328 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain+0x6a/0xa0 kernel/notifier.c:325 1 lock held by syz-executor.2/1536: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain kernel/notifier.c:328 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain+0x6a/0xa0 kernel/notifier.c:325 1 lock held by syz-executor.2/1541: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain kernel/notifier.c:328 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain+0x6a/0xa0 kernel/notifier.c:325 1 lock held by syz-executor.2/1544: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain kernel/notifier.c:328 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain+0x6a/0xa0 kernel/notifier.c:325 1 lock held by syz-executor.2/1546: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain kernel/notifier.c:328 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain+0x6a/0xa0 kernel/notifier.c:325 1 lock held by syz-executor.1/1537: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain kernel/notifier.c:328 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain+0x6a/0xa0 kernel/notifier.c:325 1 lock held by syz-executor.1/1538: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain kernel/notifier.c:328 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain+0x6a/0xa0 kernel/notifier.c:325 1 lock held by syz-executor.1/1545: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain kernel/notifier.c:328 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain+0x6a/0xa0 kernel/notifier.c:325 1 lock held by syz-executor.4/1539: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain kernel/notifier.c:328 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain+0x6a/0xa0 kernel/notifier.c:325 1 lock held by syz-executor.4/1542: #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain kernel/notifier.c:328 [inline] #0: ((task_exit_notifier).rwsem){.+.+..}, at: [<0000000023a62cf9>] blocking_notifier_call_chain+0x6a/0xa0 kernel/notifier.c:325 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 24 Comm: khungtaskd Not tainted 4.9.177+ #1 ffff8801d98d7cc8 ffffffff81b56f41 0000000000000000 0000000000000000 0000000000000000 ffffffff81099801 dffffc0000000000 ffff8801d98d7d00 ffffffff81b621dc 0000000000000000 0000000000000000 0000000000000000 Call Trace: [<0000000025719da2>] __dump_stack lib/dump_stack.c:15 [inline] [<0000000025719da2>] dump_stack+0xc1/0x120 lib/dump_stack.c:51 [<0000000070a23b2d>] nmi_cpu_backtrace.cold+0x47/0x87 lib/nmi_backtrace.c:99 [<00000000b632488d>] nmi_trigger_cpumask_backtrace+0x124/0x155 lib/nmi_backtrace.c:60 [<00000000afd5ecaf>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37 [<000000000f36b94b>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline] [<000000000f36b94b>] check_hung_task kernel/hung_task.c:126 [inline] [<000000000f36b94b>] check_hung_uninterruptible_tasks kernel/hung_task.c:183 [inline] [<000000000f36b94b>] watchdog+0x670/0xaf0 kernel/hung_task.c:263 [<0000000048dcb016>] kthread+0x278/0x310 kernel/kthread.c:211 [<00000000c374bca7>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at pc 0xffffffff82817d31