INFO: task syz-executor1:30915 blocked for more than 140 seconds. Not tainted 4.19.0+ #308 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor1 D23864 30915 5604 0x00000004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x8cf/0x21d0 kernel/sched/core.c:3480 schedule+0xfe/0x460 kernel/sched/core.c:3524 __rwsem_down_write_failed_common+0xc9a/0x15e0 kernel/locking/rwsem-xadd.c:577 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:606 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+0xa9/0x130 kernel/locking/rwsem.c:195 inode_lock_nested include/linux/fs.h:792 [inline] filename_create+0x1b2/0x5b0 fs/namei.c:3635 user_path_create fs/namei.c:3693 [inline] do_symlinkat+0xfe/0x2d0 fs/namei.c:4147 __do_sys_symlink fs/namei.c:4173 [inline] __se_sys_symlink fs/namei.c:4171 [inline] __x64_sys_symlink+0x59/0x80 fs/namei.c:4171 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457569 Code: 83 c4 18 c3 e8 d8 64 00 00 48 8b 04 24 48 8b 4c 24 08 48 89 01 e8 d7 2d fc ff e8 22 7a fc ff b8 02 00 00 00 48 8d 0d ca 96 0a <01> 87 01 8b 05 c2 96 0a 01 83 f8 01 0f 85 8a 00 00 00 b8 01 00 00 RSP: 002b:00007fae41800c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000058 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000457569 RDX: 0000000000000000 RSI: 0000000020000800 RDI: 00000000200007c0 RBP: 000000000072bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fae418016d4 R13: 00000000004c4a97 R14: 00000000004d7f70 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/982: #0: 000000007af86b6a (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379 2 locks held by rsyslogd/5460: #0: 0000000031689c8d (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 #1: 000000007de114f6 (&obj_hash[i].lock){-.-.}, at: is_bpf_text_address+0x0/0x170 kernel/bpf/core.c:530 2 locks held by getty/5549: #0: 00000000c75ebd7b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000009f050d74 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5550: #0: 0000000090087a39 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000160804c0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5551: #0: 000000007a2e0b05 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000005aff53f3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5552: #0: 000000004fa55d4b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000023c8be12 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5553: #0: 00000000172edb7d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000236dd916 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5554: #0: 00000000c78dd139 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000d346b19f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5555: #0: 000000000ef6474a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000a2c861d3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 3 locks held by syz-executor1/30880: #0: 00000000359cc427 (sb_writers#19){.+.+}, at: sb_start_write include/linux/fs.h:1585 [inline] #0: 00000000359cc427 (sb_writers#19){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360 #1: 00000000f48ebee7 (&sb->s_type->i_mutex_key#26/1){+.+.}, at: inode_lock_nested include/linux/fs.h:792 [inline] #1: 00000000f48ebee7 (&sb->s_type->i_mutex_key#26/1){+.+.}, at: do_unlinkat+0x3d8/0xa30 fs/namei.c:4049 #2: 000000007586f622 (&sb->s_type->i_mutex_key#27){++++}, at: inode_lock include/linux/fs.h:757 [inline] #2: 000000007586f622 (&sb->s_type->i_mutex_key#27){++++}, at: vfs_unlink+0xd1/0x510 fs/namei.c:3991 2 locks held by syz-executor1/30915: #0: 00000000359cc427 (sb_writers#19){.+.+}, at: sb_start_write include/linux/fs.h:1585 [inline] #0: 00000000359cc427 (sb_writers#19){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360 #1: 00000000f48ebee7 (&sb->s_type->i_mutex_key#26/1){+.+.}, at: inode_lock_nested include/linux/fs.h:792 [inline] #1: 00000000f48ebee7 (&sb->s_type->i_mutex_key#26/1){+.+.}, at: filename_create+0x1b2/0x5b0 fs/namei.c:3635 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 982 Comm: khungtaskd Not tainted 4.19.0+ #308 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+0x244/0x39d lib/dump_stack.c:113 nmi_cpu_backtrace.cold.1+0x5c/0xa1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b3/0x1ed 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:204 [inline] watchdog+0xb3e/0x1050 kernel/hung_task.c:265 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:350 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3409 Comm: udevd Not tainted 4.19.0+ #308 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:ep_poll+0x48d/0x13d0 fs/eventpoll.c:1747 Code: 91 0d 00 00 45 31 f6 48 83 bb 30 01 00 00 ff 75 77 e8 67 d8 99 ff 48 8b 7c 24 50 e8 8d 97 d7 05 e8 58 d8 99 ff 48 8b 54 24 48 <31> c0 48 bf 00 00 00 00 00 fc ff df b9 05 00 00 00 48 01 fa 48 89 RSP: 0018:ffff8801c783f9a0 EFLAGS: 00000293 RAX: ffff8801c7836440 RBX: ffff8801c7a58540 RCX: ffffffff81e56148 RDX: 1ffff10038f07f41 RSI: ffffffff81e56008 RDI: 0000000000000005 RBP: ffff8801c783fdb0 R08: ffff8801c7836440 R09: ffffed0038f4b0a8 R10: ffffed0038f4b0a8 R11: ffff8801c7a58547 R12: ffff8801c7a58650 R13: ffff8801c783fb68 R14: 0000000000000001 R15: ffffed0038f07f65 FS: 00007f912ed7e7a0(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000001c7e78000 CR4: 00000000001426e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: do_epoll_wait+0x1b0/0x200 fs/eventpoll.c:2198 __do_sys_epoll_wait fs/eventpoll.c:2208 [inline] __se_sys_epoll_wait fs/eventpoll.c:2205 [inline] __x64_sys_epoll_wait+0x97/0xf0 fs/eventpoll.c:2205 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f912e492943 Code: 00 31 d2 48 29 c2 64 89 11 48 83 c8 ff eb ea 90 90 90 90 90 90 90 90 83 3d b5 dc 2a 00 00 75 13 49 89 ca b8 e8 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 34 c3 48 83 ec 08 e8 3b c4 00 00 48 89 04 24 RSP: 002b:00007fff85a45a08 EFLAGS: 00000246 ORIG_RAX: 00000000000000e8 RAX: ffffffffffffffda RBX: 0000000000000bb8 RCX: 00007f912e492943 RDX: 0000000000000008 RSI: 00007fff85a45b00 RDI: 000000000000000a RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000bb8 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000000 R14: 0000000001e47080 R15: 0000000001e36250