INFO: task syz-executor.4:10468 blocked for more than 143 seconds. Not tainted 5.9.0-rc3-next-20200903-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:29800 pid:10468 ppid: 6890 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:00007fd7f3c7bbf8 EFLAGS: 00000206 ORIG_RAX: 00000000000001a9 RAX: ffffffffffffffda RBX: 0000000020000000 RCX: 000000000045d5b9 RDX: 0000000020ffd000 RSI: 0000000020000000 RDI: 000000000000497a RBP: 000000000118d038 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000020ffd000 R13: 0000000020831000 R14: 0000000000000000 R15: 0000000000000000 INFO: task io_uring-sq:10472 blocked for more than 143 seconds. Not tainted 5.9.0-rc3-next-20200903-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:io_uring-sq state:D stack:31120 pid:10472 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/1172: #0: ffffffff89c67500 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5829 1 lock held by in:imklog/6690: #0: ffff88809657cdb0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1172 Comm: khungtaskd Not tainted 5.9.0-rc3-next-20200903-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: 6697 Comm: rs:main Q:Reg Not tainted 5.9.0-rc3-next-20200903-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_acquire+0xd0c/0x5570 kernel/locking/lockdep.c:4296 Code: 0a 41 bf 01 00 00 00 0f 86 83 00 00 00 89 05 ab dc c9 0a eb 7b 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 80 3c 02 00 <0f> 85 ae 33 00 00 48 81 3b c0 54 f9 8b 0f 84 bb f3 ff ff 83 fe 01 RSP: 0018:ffffc9000a0ef468 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffffffff89c67500 RCX: 1ffff9200141de9f RDX: 1ffffffff138cea0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: fffffbfff15796c1 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffff888094cec480 R15: 0000000000000002 FS: 00007fc986d7f700(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa19f36e000 CR3: 0000000095122000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1f3/0xae0 kernel/locking/lockdep.c:5006 rcu_lock_acquire include/linux/rcupdate.h:248 [inline] rcu_read_lock include/linux/rcupdate.h:641 [inline] get_mem_cgroup_from_mm+0x3b/0x410 mm/memcontrol.c:1029 mem_cgroup_charge+0x18f/0x9c0 mm/memcontrol.c:6715 __add_to_page_cache_locked+0xa7c/0x10a0 mm/filemap.c:849 add_to_page_cache_lru+0x176/0x5b0 mm/filemap.c:919 pagecache_get_page+0x3ce/0xf70 mm/filemap.c:1721 grab_cache_page_write_begin+0x64/0x90 mm/filemap.c:3353 ext4_da_write_begin+0x35c/0x11d0 fs/ext4/inode.c:2965 generic_perform_write+0x20a/0x4f0 mm/filemap.c:3403 ext4_buffered_write_iter+0x235/0x4a0 fs/ext4/file.c:269 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: 0033:0x7fc9897c31cd 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:00007fc986d7e590 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fc97c0238a0 RCX: 00007fc9897c31cd RDX: 000000000000044d RSI: 00007fc97c0238a0 RDI: 0000000000000006 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 00007fc97c023620 R13: 00007fc986d7e5b0 R14: 000055ff66eb5360 R15: 000000000000044d