INFO: task syz-executor.2:13737 blocked for more than 143 seconds. Not tainted 5.6.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28328 13737 7425 0x80004004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4154 schedule_timeout+0x6db/0xba0 kernel/time/timer.c:1871 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x26a/0x3c0 kernel/sched/completion.c:136 io_queue_file_removal+0x1af/0x1e0 fs/io_uring.c:5840 __io_sqe_files_update.isra.0+0x3a1/0xb00 fs/io_uring.c:5881 io_sqe_files_update fs/io_uring.c:5932 [inline] __io_uring_register+0x377/0x2c00 fs/io_uring.c:7145 __do_sys_io_uring_register fs/io_uring.c:7216 [inline] __se_sys_io_uring_register fs/io_uring.c:7198 [inline] __x64_sys_io_uring_register+0x192/0x560 fs/io_uring.c:7198 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c849 Code: Bad RIP value. RSP: 002b:00007f21b7422c78 EFLAGS: 00000246 ORIG_RAX: 00000000000001ab RAX: ffffffffffffffda RBX: 00007f21b74236d4 RCX: 000000000045c849 RDX: 0000000020000300 RSI: 0000000000000006 RDI: 0000000000000003 RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000009 R13: 00000000000001fe R14: 00000000004d2f28 R15: 0000000000000000 Showing all locks held in the system: 2 locks held by kworker/u4:0/7: #0: ffff8880ae637518 (&rq->lock){-.-.}, at: newidle_balance+0x9d9/0xdd0 kernel/sched/fair.c:10221 #1: ffffffff897accc0 (rcu_read_lock){....}, at: __update_idle_core+0x42/0x3e0 kernel/sched/fair.c:5747 1 lock held by khungtaskd/1139: #0: ffffffff897accc0 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5331 1 lock held by in:imklog/6776: #0: ffff88809a8ec8a0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:826 2 locks held by rs:main Q:Reg/6777: 2 locks held by agetty/6842: #0: ffff8880a7e5a090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc90000f002e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.2/13737: #0: ffff888094c9e320 (&ctx->uring_lock){+.+.}, at: __do_sys_io_uring_register fs/io_uring.c:7215 [inline] #0: ffff888094c9e320 (&ctx->uring_lock){+.+.}, at: __se_sys_io_uring_register fs/io_uring.c:7198 [inline] #0: ffff888094c9e320 (&ctx->uring_lock){+.+.}, at: __x64_sys_io_uring_register+0x181/0x560 fs/io_uring.c:7198 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1139 Comm: khungtaskd Not tainted 5.6.0-rc7-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+0x188/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x231/0x27e lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xa8c/0x1010 kernel/hung_task.c:289 kthread+0x357/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4188 Comm: systemd-journal Not tainted 5.6.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:clear_page_erms+0x7/0x10 arch/x86/lib/clear_page_64.S:49 Code: 48 89 47 18 48 89 47 20 48 89 47 28 48 89 47 30 48 89 47 38 48 8d 7f 40 75 d9 90 c3 0f 1f 80 00 00 00 00 b9 00 10 00 00 31 c0 aa c3 cc cc cc cc cc cc 41 57 41 56 41 55 41 54 55 53 48 89 fb RSP: 0018:ffffc900015d7958 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ffffea0001142b40 RCX: 0000000000000840 RDX: 1ffff11014fa0aab RSI: 0000000000000002 RDI: ffff8880450ad7c0 RBP: ffff8880a7d04300 R08: ffff8880a7d04300 R09: ffffed1008a15800 R10: fffff94000228566 R11: ffffea0001142b37 R12: ffffed1014fa0add R13: dffffc0000000000 R14: ffffea0001142b80 R15: ffff8880a7d056e8 FS: 00007fe1e53f78c0(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe1e2814000 CR3: 00000000a790a000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: clear_page arch/x86/include/asm/page_64.h:49 [inline] clear_highpage include/linux/highmem.h:214 [inline] kernel_init_free_pages+0x92/0x120 mm/page_alloc.c:1118 prep_new_page+0x12e/0x1f0 mm/page_alloc.c:2160 get_page_from_freelist+0x2d02/0x3ee0 mm/page_alloc.c:3684 __alloc_pages_nodemask+0x2a5/0x820 mm/page_alloc.c:4731 __alloc_pages include/linux/gfp.h:496 [inline] __alloc_pages_node include/linux/gfp.h:509 [inline] kmem_getpages mm/slab.c:1367 [inline] cache_grow_begin+0x8c/0xc30 mm/slab.c:2600 cache_alloc_refill mm/slab.c:2972 [inline] ____cache_alloc mm/slab.c:3055 [inline] ____cache_alloc mm/slab.c:3038 [inline] __do_cache_alloc mm/slab.c:3277 [inline] slab_alloc mm/slab.c:3312 [inline] kmem_cache_alloc+0x66a/0x730 mm/slab.c:3484 getname_flags fs/namei.c:138 [inline] getname_flags+0xd2/0x5b0 fs/namei.c:128 do_sys_openat2+0x3cf/0x740 fs/open.c:1140 do_sys_open+0xc3/0x140 fs/open.c:1162 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fe1e4987840 Code: 73 01 c3 48 8b 0d 68 77 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 89 bb 20 00 00 75 10 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 1e f6 ff ff 48 89 04 24 RSP: 002b:00007ffce6049e68 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007ffce604a170 RCX: 00007fe1e4987840 RDX: 00000000000001a0 RSI: 0000000000080042 RDI: 00005651f25fdb10 RBP: 000000000000000d R08: 0000000000000000 R09: 00000000ffffffff R10: 0000000000000069 R11: 0000000000000246 R12: 00000000ffffffff R13: 00005651f25f8060 R14: 00007ffce604a130 R15: 00005651f25fdb80