INFO: task syz-executor.4:15532 blocked for more than 143 seconds. Not tainted 5.9.0-rc3-next-20200902-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:29736 pid:15532 ppid: 6894 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:3777 [inline] __schedule+0xea9/0x2230 kernel/sched/core.c:4526 schedule+0xd0/0x2a0 kernel/sched/core.c:4601 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1855 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x163/0x260 kernel/sched/completion.c:138 io_sq_thread_stop fs/io_uring.c:6906 [inline] io_finish_async fs/io_uring.c:6920 [inline] io_sq_offload_create fs/io_uring.c:7595 [inline] io_uring_create fs/io_uring.c:8671 [inline] io_uring_setup+0x1495/0x29a0 fs/io_uring.c:8744 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45d5b9 Code: Bad RIP value. RSP: 002b:00007fcb6500fc78 EFLAGS: 00000246 ORIG_RAX: 00000000000001a9 RAX: ffffffffffffffda RBX: 0000000000008540 RCX: 000000000045d5b9 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 000000000080778c RBP: 000000000118d018 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cfec R13: 00007ffd30b06dff R14: 00007fcb650109c0 R15: 000000000118cfec INFO: task io_uring-sq:15533 blocked for more than 143 seconds. Not tainted 5.9.0-rc3-next-20200902-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:io_uring-sq state:D stack:31120 pid:15533 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:3777 [inline] __schedule+0xea9/0x2230 kernel/sched/core.c:4526 schedule+0xd0/0x2a0 kernel/sched/core.c:4601 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4660 kthread+0x2ac/0x4a0 kernel/kthread.c:285 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Showing all locks held in the system: 1 lock held by khungtaskd/1175: #0: ffffffff89c67980 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5829 1 lock held by in:imklog/6552: 2 locks held by rs:main Q:Reg/6553: #0: ffff8880a30a1e30 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930 #1: ffff8880980c6460 (sb_writers#4){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2793 [inline] #1: ffff8880980c6460 (sb_writers#4){.+.+}-{0:0}, at: vfs_write+0x54f/0x730 fs/read_write.c:574 2 locks held by agetty/6788: #0: ffff8880975cc098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:266 #1: ffffc90001a872e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x223/0x1a30 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1175 Comm: khungtaskd Not tainted 5.9.0-rc3-next-20200902-syzkaller #0 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+0x198/0x1fd lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:147 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:253 [inline] watchdog+0xd89/0xf30 kernel/hung_task.c:339 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 6553 Comm: rs:main Q:Reg Not tainted 5.9.0-rc3-next-20200902-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_is_held kernel/locking/lockdep.c:4779 [inline] RIP: 0010:lock_is_held_type+0x72/0xf0 kernel/locking/lockdep.c:5045 Code: 00 00 85 c0 7f 0d eb 7d 83 c3 01 3b 9d 08 09 00 00 7d 72 48 63 c3 4c 89 e6 48 8d 04 80 4d 8d 74 c5 00 4c 89 f7 e8 4e fc ff ff <85> c0 74 da 8b 4c 24 04 41 bc 01 00 00 00 83 f9 ff 74 11 41 0f b6 RSP: 0018:ffffc90009ca7420 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffffffff130b120 RDX: dffffc0000000000 RSI: ffffffff89c678c0 RDI: ffff8880a2bc4e10 RBP: ffff8880a2bc4500 R08: 0000000000000000 R09: ffffffff8abcba4f R10: fffffbfff1579749 R11: 0000000000000000 R12: ffffffff89c678c0 R13: ffff8880a2bc4e10 R14: ffff8880a2bc4e10 R15: 0000000000000282 FS: 00007fcd34be5700(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc059f01018 CR3: 0000000096631000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_is_held include/linux/lockdep.h:267 [inline] rcu_read_lock_sched_held+0x3a/0xb0 kernel/rcu/update.c:123 trace_lock_acquire include/trace/events/lock.h:13 [inline] lock_acquire+0x82a/0xae0 kernel/locking/lockdep.c:4980 rcu_lock_acquire include/linux/rcupdate.h:248 [inline] rcu_read_lock include/linux/rcupdate.h:641 [inline] blk_partition_remap block/blk-core.c:746 [inline] submit_bio_checks+0x643/0x1f70 block/blk-core.c:827 submit_bio_noacct+0x89/0x12b0 block/blk-core.c:1042 submit_bio+0x263/0x5b0 block/blk-core.c:1127 submit_bh_wbc+0x685/0x8e0 fs/buffer.c:3107 submit_bh fs/buffer.c:3113 [inline] __sync_dirty_buffer+0x168/0x3e0 fs/buffer.c:3208 ext4_write_inode+0x4ee/0x5a0 fs/ext4/inode.c:5165 write_inode fs/fs-writeback.c:1320 [inline] __writeback_single_inode+0xd10/0x1400 fs/fs-writeback.c:1516 writeback_single_inode+0x2a5/0x450 fs/fs-writeback.c:1570 sync_inode fs/fs-writeback.c:2605 [inline] sync_inode_metadata+0x93/0xd0 fs/fs-writeback.c:2625 ext4_fsync_nojournal fs/ext4/fsync.c:92 [inline] ext4_sync_file+0x7c6/0x1090 fs/ext4/fsync.c:170 vfs_fsync_range+0x13a/0x220 fs/sync.c:200 generic_write_sync include/linux/fs.h:2757 [inline] ext4_buffered_write_iter+0x34a/0x4a0 fs/ext4/file.c:276 ext4_file_write_iter+0x1f0/0x13f0 fs/ext4/file.c:660 call_write_iter include/linux/fs.h:1892 [inline] new_sync_write+0x422/0x650 fs/read_write.c:503 vfs_write+0x5ad/0x730 fs/read_write.c:578 ksys_write+0x12d/0x250 fs/read_write.c:631 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7fcd376291cd Code: c2 20 00 00 75 10 b8 01 00 00 00 0f 05 48 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 ae fc ff ff 48 89 04 24 b8 01 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 f7 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007fcd34be4590 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fcd2c0245f0 RCX: 00007fcd376291cd RDX: 000000000000088a RSI: 00007fcd2c0245f0 RDI: 0000000000000006 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 00007fcd2c024370 R13: 00007fcd34be45b0 R14: 00005560b978f360 R15: 000000000000088a