INFO: task syz-executor1:10100 blocked for more than 140 seconds. Not tainted 4.19.0-rc7+ #59 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor1 D23512 10100 5427 0x00000004 Call Trace: context_switch kernel/sched/core.c:2825 [inline] __schedule+0x86c/0x1ed0 kernel/sched/core.c:3473 schedule+0xfe/0x460 kernel/sched/core.c:3517 blk_mq_freeze_queue_wait+0x1d4/0x460 block/blk-mq.c:152 blk_freeze_queue+0x4a/0x80 block/blk-mq.c:181 blk_mq_freeze_queue+0x15/0x20 block/blk-mq.c:190 loop_set_status+0x1ff/0x1010 drivers/block/loop.c:1131 loop_set_status64+0xaa/0x100 drivers/block/loop.c:1317 lo_ioctl+0x90e/0x1d80 drivers/block/loop.c:1433 __blkdev_driver_ioctl block/ioctl.c:303 [inline] blkdev_ioctl+0x9ac/0x2010 block/ioctl.c:601 block_ioctl+0xee/0x130 fs/block_dev.c:1883 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702 __do_sys_ioctl fs/ioctl.c:709 [inline] __se_sys_ioctl fs/ioctl.c:707 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457569 Code: Bad RIP value. RSP: 002b:00007f32bd5ecc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457569 RDX: 0000000020000240 RSI: 0000000000004c04 RDI: 0000000000000005 RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f32bd5ed6d4 R13: 00000000004c0481 R14: 00000000004d0630 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/982: #0: 00000000b1a0815b (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4435 1 lock held by rsyslogd/5290: #0: 000000000d0c8c52 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/5380: #0: 0000000097d2baee (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000dc942666 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5381: #0: 00000000ea491176 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000f2691457 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5382: #0: 00000000768d5e39 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000e6fed0fb (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5383: #0: 00000000ce214a26 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000bba28ceb (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5384: #0: 0000000044fb9597 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000a554aec6 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5385: #0: 0000000022d8353b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000d3b2516a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5386: #0: 00000000b4967e23 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000002a23878d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 3 locks held by kworker/u4:5/9747: 1 lock held by syz-executor1/10100: #0: 000000009b7e2008 (&lo->lo_ctl_mutex/1){+.+.}, at: lo_ioctl+0x8e/0x1d80 drivers/block/loop.c:1403 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 982 Comm: khungtaskd Not tainted 4.19.0-rc7+ #59 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+0x1c4/0x2b4 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.3+0x63/0xa2 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/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: INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 2.386 msecs NMI backtrace for cpu 0 CPU: 0 PID: 9747 Comm: kworker/u4:5 Not tainted 4.19.0-rc7+ #59 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: writeback wb_workfn (flush-7:0) RIP: 0010:__read_once_size include/linux/compiler.h:188 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:69 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x26/0x50 kernel/kcov.c:101 Code: 5d c3 66 90 55 48 89 e5 65 48 8b 04 25 40 ee 01 00 65 8b 15 6c 44 83 7e 81 e2 00 01 1f 00 48 8b 75 08 75 2b 8b 90 d0 12 00 00 <83> fa 02 75 20 48 8b 88 d8 12 00 00 8b 80 d4 12 00 00 48 8b 11 48 RSP: 0018:ffff880181725b48 EFLAGS: 00000246 RAX: ffff880183bbe380 RBX: ffffea0006d4ab00 RCX: ffffffff81a4ed66 RDX: 0000000000000000 RSI: ffffffff81a4ed75 RDI: 0000000000000007 RBP: ffff880181725b48 R08: ffff880183bbe380 R09: ffffed003b5c4732 R10: ffffed003b5c4732 R11: ffff8801dae23993 R12: ffff880181726050 R13: ffffea0006d4ab08 R14: 1ffff100302e4b6e R15: 02fffc000001106d FS: 0000000000000000(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f158751f800 CR3: 00000001d7579000 CR4: 00000000001406f0 Call Trace: compound_head include/linux/page-flags.h:142 [inline] PageReferenced include/linux/page-flags.h:275 [inline] mark_page_accessed+0xdd5/0x2040 mm/swap.c:396 pagecache_get_page+0x7cd/0xf00 mm/filemap.c:1567 find_or_create_page include/linux/pagemap.h:322 [inline] grow_dev_page fs/buffer.c:947 [inline] grow_buffers fs/buffer.c:1016 [inline] __getblk_slow fs/buffer.c:1043 [inline] __getblk_gfp+0x3b0/0xd50 fs/buffer.c:1320 __bread_gfp+0x2d/0x300 fs/buffer.c:1354 sb_bread include/linux/buffer_head.h:307 [inline] __fat_write_inode+0x347/0xb60 fs/fat/inode.c:859 fat_write_inode+0x97/0x180 fs/fat/inode.c:908 write_inode fs/fs-writeback.c:1183 [inline] __writeback_single_inode+0xf1f/0x1620 fs/fs-writeback.c:1382 writeback_sb_inodes+0x71f/0x11d0 fs/fs-writeback.c:1587 __writeback_inodes_wb+0x1b9/0x340 fs/fs-writeback.c:1656 wb_writeback+0xa73/0xfc0 fs/fs-writeback.c:1765 wb_check_old_data_flush fs/fs-writeback.c:1867 [inline] wb_do_writeback fs/fs-writeback.c:1920 [inline] wb_workfn+0x1008/0x1790 fs/fs-writeback.c:1949 process_one_work+0xc90/0x1b90 kernel/workqueue.c:2153 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296 kthread+0x35a/0x420 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413