INFO: task syz-executor.3:15625 blocked for more than 140 seconds. Not tainted 4.9.141+ #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D29592 15625 15621 0x00000000 ffff8801420817c0 ffff8801d091ac00 ffff8800aee26300 ffff88017d0917c0 ffff8801db721018 ffff8801d12bf840 ffffffff828075c2 ffff8801d9c4e980 ffffffff83cd4aa0 0000000000000246 0000000000001529 ffff8801db7218f0 Call Trace: [] schedule+0x7f/0x1b0 kernel/sched/core.c:3553 [] schedule_timeout+0x735/0xe20 kernel/time/timer.c:1771 [] down_read_failed drivers/tty/tty_ldsem.c:241 [inline] [] __ldsem_down_read_nested+0x33c/0x610 drivers/tty/tty_ldsem.c:332 [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 [] tty_ldisc_ref_wait+0x25/0x80 drivers/tty/tty_ldisc.c:275 [] tty_ioctl+0x3b6/0x2190 drivers/tty/tty_io.c:3009 [] vfs_ioctl fs/ioctl.c:43 [inline] [] file_ioctl fs/ioctl.c:493 [inline] [] do_vfs_ioctl+0x1ac/0x11a0 fs/ioctl.c:677 [] SYSC_ioctl fs/ioctl.c:694 [inline] [] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685 [] do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285 [] 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: [] rcu_read_unlock include/linux/rcupdate.h:927 [inline] #0: (rcu_read_lock){......}, at: [] rcu_lock_break kernel/hung_task.c:143 [inline] #0: (rcu_read_lock){......}, at: [] check_hung_uninterruptible_tasks kernel/hung_task.c:177 [inline] #0: (rcu_read_lock){......}, at: [] watchdog+0x310/0xa20 kernel/hung_task.c:239 #1: (tasklist_lock){.+.+..}, at: [] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336 1 lock held by rsyslogd/1897: #0: (&f->f_pos_lock){+.+.+.}, at: [] __fdget_pos+0xac/0xd0 fs/file.c:781 2 locks held by getty/2024: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 1 lock held by syz-executor.4/2090: #0: (&rq->lock){-.-.-.}, at: [] lock_hrtimer_base.isra.1+0x75/0x130 kernel/time/hrtimer.c:145 2 locks held by kworker/1:0/5677: #0: ("events"){.+.+.+}, at: [] process_one_work+0x73c/0x15f0 kernel/workqueue.c:2085 #1: ((&rew.rew_work)){+.+...}, at: [] process_one_work+0x774/0x15f0 kernel/workqueue.c:2089 3 locks held by kworker/0:4/8290: #0: ("events"){.+.+.+}, at: [] process_one_work+0x73c/0x15f0 kernel/workqueue.c:2085 #1: ((linkwatch_work).work){+.+...}, at: [] process_one_work+0x774/0x15f0 kernel/workqueue.c:2089 #2: (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70 2 locks held by syz-executor.3/15621: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 1 lock held by syz-executor.3/15625: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 2 locks held by syz-executor.0/18506: #0: (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70 #1: (rcu_preempt_state.exp_mutex){+.+...}, at: [] exp_funnel_lock kernel/rcu/tree_exp.h:256 [inline] #1: (rcu_preempt_state.exp_mutex){+.+...}, at: [] _synchronize_rcu_expedited+0x339/0x840 kernel/rcu/tree_exp.h:569 2 locks held by syz-executor.2/18526: #0: (sb_writers#4){.+.+.+}, at: [] file_start_write include/linux/fs.h:2640 [inline] #0: (sb_writers#4){.+.+.+}, at: [] do_sendfile+0xa80/0xc30 fs/read_write.c:1392 #1: (&sb->s_type->i_mutex_key#9){++++++}, at: [] inode_lock include/linux/fs.h:766 [inline] #1: (&sb->s_type->i_mutex_key#9){++++++}, at: [] __generic_file_fsync+0xc1/0x1a0 fs/libfs.c:978 1 lock held by syz-executor.2/18536: #0: (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70 1 lock held by syz-executor.3/18530: #0: (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70 1 lock held by syz-executor.1/18532: #0: (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 24 Comm: khungtaskd Not tainted 4.9.141+ #1 ffff8801d9907d08 ffffffff81b42e79 0000000000000000 0000000000000000 0000000000000000 0000000000000001 ffffffff810983b0 ffff8801d9907d40 ffffffff81b4df89 0000000000000000 0000000000000000 0000000000000002 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x128 lib/dump_stack.c:51 [] nmi_cpu_backtrace.cold.0+0x48/0x87 lib/nmi_backtrace.c:99 [] nmi_trigger_cpumask_backtrace+0x12c/0x151 lib/nmi_backtrace.c:60 [] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37 [] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline] [] check_hung_task kernel/hung_task.c:125 [inline] [] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline] [] watchdog+0x6ad/0xa20 kernel/hung_task.c:239 [] kthread+0x26d/0x300 kernel/kthread.c:211 [] 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 CPU: 1 PID: 2089 Comm: syz-executor.3 Not tainted 4.9.141+ #1 task: ffff8801d7868000 task.stack: ffff8801aa748000 RIP: 0010:[] c [] get_current arch/x86/include/asm/current.h:14 [inline] RIP: 0010:[] c [] debug_lockdep_rcu_enabled.part.0+0xf/0x60 kernel/rcu/update.c:265 RSP: 0018:ffff8801aa74fa18 EFLAGS: 00000202 RAX: dffffc0000000000 RBX: 1ffff100354e9f4e RCX: 0000000000000000 RDX: 0000000000000004 RSI: ffffffff819edb0d RDI: ffffffff831f2500 RBP: ffff8801aa74fa20 R08: ffffed00354e9f55 R09: ffffed00354e9f52 R10: ffffed00354e9f54 R11: 0000000000000003 R12: 0000000000000004 R13: ffff8801aa74fb30 R14: 0000000000000002 R15: 0000000000000000 FS: 0000000000daf940(0000) GS:ffff8801db700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff311f85db8 CR3: 00000001aa52e000 CR4: 00000000001606b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: 1ffff100354e9f4ec ffff8801aa74fa30c ffffffff81243c87c ffff8801aa74fb58c ffffffff819edb12c ffffffff819eda5ec ffff8801d78688b0c 0000000000000003c 0000000000000000c ffff8801aa74fa90c 000000cf000000cfc 0000000041b58ab3c Call Trace: [] debug_lockdep_rcu_enabled+0x77/0x90 kernel/rcu/update.c:264 [] rcu_read_unlock include/linux/rcupdate.h:927 [inline] [] avc_has_perm_noaudit security/selinux/avc.c:1120 [inline] [] avc_has_perm+0x152/0x3a0 security/selinux/avc.c:1146 [] task_has_perm+0x1fc/0x330 security/selinux/hooks.c:1615 [] selinux_task_wait+0x23/0x30 security/selinux/hooks.c:3954 [] security_task_wait+0x73/0xb0 security/security.c:1032 [] wait_consider_task+0x2a1/0x3620 kernel/exit.c:1377 [] do_wait_thread kernel/exit.c:1490 [inline] [] do_wait+0x423/0x950 kernel/exit.c:1561 [] SYSC_wait4 kernel/exit.c:1693 [inline] [] SyS_wait4+0x12b/0x1f0 kernel/exit.c:1658 [] do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285 [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb Code: cff cff c4c c89 cef ce8 cc2 cf4 c2a c00 ce9 c77 cff cff cff c48 c89 cdf ce8 cb5 cf4 c2a c00 ce9 ca7 cfe cff cff c48 cb8 c00 c00 c00 c00 c00 cfc cff cdf c55 c48 c89 ce5 c53 c<65> c48 c8b c1c c25 c00 c7e c01 c00 c48 c8d cbb cac c08 c00 c00 c48 c89 cfa c48 cc1 c