INFO: task syz-executor2:27435 blocked for more than 140 seconds. Not tainted 4.18.0+ #187 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor2 D25408 27435 4464 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:750 [inline] do_unlinkat+0x3d8/0xa30 fs/namei.c:4059 __do_sys_unlink fs/namei.c:4120 [inline] __se_sys_unlink fs/namei.c:4118 [inline] __x64_sys_unlink+0x42/0x50 fs/namei.c:4118 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:00007fb67bad0c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 00007fb67bad16d4 RCX: 0000000000457089 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000300 RBP: 0000000000930140 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d6810 R14: 00000000004c78bd R15: 0000000000000001 INFO: task syz-executor2:27489 blocked for more than 140 seconds. Not tainted 4.18.0+ #187 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor2 D24216 27489 4464 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:750 [inline] filename_create+0x1b2/0x5b0 fs/namei.c:3645 user_path_create fs/namei.c:3703 [inline] do_symlinkat+0xfe/0x2d0 fs/namei.c:4157 __do_sys_symlink fs/namei.c:4183 [inline] __se_sys_symlink fs/namei.c:4181 [inline] __x64_sys_symlink+0x59/0x80 fs/namei.c:4181 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:00007fb67baafc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000058 RAX: ffffffffffffffda RBX: 00007fb67bab06d4 RCX: 0000000000457089 RDX: 0000000000000000 RSI: 0000000020000800 RDI: 00000000200007c0 RBP: 00000000009301e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d5eb0 R14: 00000000004c988b R15: 0000000000000002 Showing all locks held in the system: 1 lock held by khungtaskd/771: #0: 000000005c10d95b (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4461 1 lock held by rsyslogd/4326: 2 locks held by getty/4417: #0: 000000001c3e0582 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000061dd9a7d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4418: #0: 000000007c4b2538 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000c8abba73 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4419: #0: 00000000ea48bc8f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000aa39f887 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4420: #0: 00000000f95e6960 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000003dca911c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4421: #0: 0000000046eda0c7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000a5caf5ad (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4422: #0: 0000000025b2e498 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000005914e4f6 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4423: #0: 00000000a48fdb66 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000911def80 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by syz-executor2/27428: #0: 000000008505ee3e (sb_writers#17){.+.+}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 000000008505ee3e (sb_writers#17){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 00000000c5c7c620 (&sb->s_type->i_mutex_key#20/1){+.+.}, at: inode_lock_nested include/linux/fs.h:750 [inline] #1: 00000000c5c7c620 (&sb->s_type->i_mutex_key#20/1){+.+.}, at: filename_create+0x1b2/0x5b0 fs/namei.c:3645 2 locks held by syz-executor2/27435: #0: 000000008505ee3e (sb_writers#17){.+.+}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 000000008505ee3e (sb_writers#17){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 00000000c5c7c620 (&sb->s_type->i_mutex_key#20/1){+.+.}, at: inode_lock_nested include/linux/fs.h:750 [inline] #1: 00000000c5c7c620 (&sb->s_type->i_mutex_key#20/1){+.+.}, at: do_unlinkat+0x3d8/0xa30 fs/namei.c:4059 2 locks held by syz-executor2/27489: #0: 000000008505ee3e (sb_writers#17){.+.+}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 000000008505ee3e (sb_writers#17){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 00000000c5c7c620 (&sb->s_type->i_mutex_key#20/1){+.+.}, at: inode_lock_nested include/linux/fs.h:750 [inline] #1: 00000000c5c7c620 (&sb->s_type->i_mutex_key#20/1){+.+.}, at: filename_create+0x1b2/0x5b0 fs/namei.c:3645 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 771 Comm: khungtaskd Not tainted 4.18.0+ #187 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.4+0x19/0xce lib/nmi_backtrace.c:103 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 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54