INFO: task syz-executor1:12149 blocked for more than 140 seconds. Not tainted 4.18.0+ #195 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor1 D22464 12149 4472 0x00000004 Call Trace: context_switch kernel/sched/core.c:2823 [inline] __schedule+0x87c/0x1ec0 kernel/sched/core.c:3471 schedule+0xfb/0x450 kernel/sched/core.c:3515 __rwsem_down_write_failed_common+0x98b/0x1650 kernel/locking/rwsem-xadd.c:566 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:595 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write_nested+0xae/0x130 kernel/locking/rwsem.c:194 inode_lock_nested include/linux/fs.h:768 [inline] do_unlinkat+0x3d8/0xa30 fs/namei.c:4002 __do_sys_unlink fs/namei.c:4063 [inline] __se_sys_unlink fs/namei.c:4061 [inline] __x64_sys_unlink+0x42/0x50 fs/namei.c:4061 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457089 Code: 08 e8 3b a9 fb ff 48 8b 44 24 20 48 8b 4c 24 18 48 8b 54 24 38 48 8b 7c 24 48 eb 8d 48 8b 6c 24 50 48 83 c4 58 c3 48 89 04 24 <48> 89 5c 24 08 e8 0d a9 fb ff 48 8b 44 24 40 48 8b 4c 24 48 48 8b RSP: 002b:00007fd8aa1a3c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 00007fd8aa1a46d4 RCX: 0000000000457089 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200002c0 RBP: 00000000009301e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d6c80 R14: 00000000004c7a6c R15: 0000000000000002 Showing all locks held in the system: 2 locks held by kworker/0:1/13: #0: 000000002ff83e14 ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:215 [inline] #0: 000000002ff83e14 ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000002ff83e14 ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 000000002ff83e14 ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 000000002ff83e14 ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 000000002ff83e14 ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 000000002ff83e14 ((wq_completion)"events"){+.+.}, at: process_one_work+0xb44/0x1ba0 kernel/workqueue.c:2124 #1: 00000000f611c94c ((work_completion)(&smc->tcp_listen_work)){+.+.}, at: process_one_work+0xb9b/0x1ba0 kernel/workqueue.c:2128 1 lock held by khungtaskd/774: #0: 000000002778e051 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4461 2 locks held by kworker/0:2/1879: #0: 000000002ff83e14 ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:215 [inline] #0: 000000002ff83e14 ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000002ff83e14 ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 000000002ff83e14 ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 000000002ff83e14 ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 000000002ff83e14 ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 000000002ff83e14 ((wq_completion)"events"){+.+.}, at: process_one_work+0xb44/0x1ba0 kernel/workqueue.c:2124 #1: 00000000a077a742 ((work_completion)(&smc->tcp_listen_work)){+.+.}, at: process_one_work+0xb9b/0x1ba0 kernel/workqueue.c:2128 1 lock held by rsyslogd/4335: #0: 000000007fca0d4b (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/4426: #0: 0000000058bda981 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000063f5ab33 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4427: #0: 000000001dcd5b57 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000cbe5b9c2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4428: #0: 00000000b4e1be90 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000001d3091d1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4429: #0: 0000000069153c04 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000728d68e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4430: #0: 000000008576986d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000020a62806 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4431: #0: 00000000c28d0a11 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000008ed2881d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4432: #0: 00000000a50f3c8b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000815cb7aa (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 3 locks held by syz-executor1/12081: #0: 00000000283134b9 (sb_writers#21){.+.+}, at: sb_start_write include/linux/fs.h:1572 [inline] #0: 00000000283134b9 (sb_writers#21){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 000000001eae18d9 (&sb->s_type->i_mutex_key#18/1){+.+.}, at: inode_lock_nested include/linux/fs.h:768 [inline] #1: 000000001eae18d9 (&sb->s_type->i_mutex_key#18/1){+.+.}, at: do_unlinkat+0x3d8/0xa30 fs/namei.c:4002 #2: 000000000e092eaa (&sb->s_type->i_mutex_key#18){++++}, at: inode_lock include/linux/fs.h:733 [inline] #2: 000000000e092eaa (&sb->s_type->i_mutex_key#18){++++}, at: vfs_unlink+0xd1/0x510 fs/namei.c:3944 2 locks held by syz-executor1/12149: #0: 00000000283134b9 (sb_writers#21){.+.+}, at: sb_start_write include/linux/fs.h:1572 [inline] #0: 00000000283134b9 (sb_writers#21){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 000000001eae18d9 (&sb->s_type->i_mutex_key#18/1){+.+.}, at: inode_lock_nested include/linux/fs.h:768 [inline] #1: 000000001eae18d9 (&sb->s_type->i_mutex_key#18/1){+.+.}, at: do_unlinkat+0x3d8/0xa30 fs/namei.c:4002 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 774 Comm: khungtaskd Not tainted 4.18.0+ #195 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.3+0x48/0x88 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x151/0x192 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:144 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:196 [inline] watchdog+0x9c4/0xf80 kernel/hung_task.c:252 kthread+0x35a/0x420 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:56