INFO: task syz-executor.0:22893 blocked for more than 140 seconds. Not tainted 4.14.228-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28456 22893 8004 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 mount_bdev+0x71/0x360 fs/super.c:1101 mount_fs+0x92/0x2a0 fs/super.c:1237 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2549 [inline] do_mount+0xe53/0x2a00 fs/namespace.c:2879 SYSC_mount fs/namespace.c:3095 [inline] SyS_mount+0xa8/0x120 fs/namespace.c:3072 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x466459 RSP: 002b:00007f1e136b4188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 0000000000466459 RDX: 0000000020000000 RSI: 0000000020000180 RDI: 0000000020000380 RBP: 00000000004bf9fb R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c008 R13: 00007fff44b587df R14: 00007f1e136b4300 R15: 0000000000022000 INFO: task syz-executor.1:22885 blocked for more than 140 seconds. Not tainted 4.14.228-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28880 22885 8006 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:588 [inline] rwsem_down_write_failed+0x343/0x6d0 kernel/locking/rwsem-xadd.c:617 call_rwsem_down_write_failed+0x13/0x20 arch/x86/lib/rwsem.S:105 __down_write arch/x86/include/asm/rwsem.h:126 [inline] down_write+0x4f/0x90 kernel/locking/rwsem.c:56 grab_super+0x55/0x140 fs/super.c:373 sget_userns+0x2b1/0xc10 fs/super.c:504 sget+0xd1/0x110 fs/super.c:572 mount_bdev+0xcd/0x360 fs/super.c:1107 mount_fs+0x92/0x2a0 fs/super.c:1237 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2549 [inline] do_mount+0xe53/0x2a00 fs/namespace.c:2879 SYSC_mount fs/namespace.c:3095 [inline] SyS_mount+0xa8/0x120 fs/namespace.c:3072 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x46797a RSP: 002b:00007ff29998bfa8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000020000600 RCX: 000000000046797a RDX: 00000000200000c0 RSI: 0000000020000100 RDI: 00007ff29998c000 RBP: 00007ff29998c040 R08: 00007ff29998c040 R09: 00000000200000c0 R10: 0000000000000000 R11: 0000000000000206 R12: 00000000200000c0 R13: 0000000020000100 R14: 00007ff29998c000 R15: 00000000200006c0 Showing all locks held in the system: 1 lock held by khungtaskd/1533: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 2 locks held by agetty/7926: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e3/0x1680 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.0/22893: #0: (&bdev->bd_fsfreeze_mutex){+.+.}, at: [] mount_bdev+0x71/0x360 fs/super.c:1101 2 locks held by syz-executor.1/22885: #0: (&bdev->bd_fsfreeze_mutex){+.+.}, at: [] mount_bdev+0x71/0x360 fs/super.c:1101 #1: (&type->s_umount_key#74){+.+.}, at: [] grab_super+0x55/0x140 fs/super.c:373 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1533 Comm: khungtaskd Not tainted 4.14.228-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x180 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5b9/0xb40 kernel/hung_task.c:274 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 22879 Comm: syz-executor.0 Not tainted 4.14.228-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff88804a476440 task.stack: ffff88804acd8000 RIP: 0010:__sanitizer_cov_trace_pc+0x15/0x50 kernel/kcov.c:65 RSP: 0018:ffff88804acdf688 EFLAGS: 00000282 RAX: ffff88804a476440 RBX: ffff88804a476440 RCX: ffffc90005af1000 RDX: 0000000080000001 RSI: ffffffff83195535 RDI: ffffffff87ccea40 RBP: ffffffff87ccea40 R08: 0000000000000000 R09: 0000000000020012 R10: ffff88804a476cf0 R11: ffff88804a476440 R12: 0000000000000000 R13: ffffffff87ccea00 R14: dffffc0000000000 R15: 0000000000000040 FS: 00007f1e136d5700(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9f20164000 CR3: 00000000b2809000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: check_preemption_disabled+0x30/0x240 lib/smp_processor_id.c:26 rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:360 [inline] rcu_is_watching+0x11/0xb0 kernel/rcu/tree.c:1130 rcu_read_lock_held+0xba/0x110 kernel/rcu/update.c:328 radix_tree_deref_slot include/linux/radix-tree.h:238 [inline] find_get_entry+0x357/0x630 mm/filemap.c:1357 pagecache_get_page+0x53/0xab0 mm/filemap.c:1465 find_or_create_page include/linux/pagemap.h:326 [inline] grow_dev_page fs/buffer.c:1004 [inline] grow_buffers fs/buffer.c:1077 [inline] __getblk_slow+0x1dd/0x7a0 fs/buffer.c:1104 __getblk_gfp fs/buffer.c:1383 [inline] __bread_gfp+0x206/0x2e0 fs/buffer.c:1428 sb_bread include/linux/buffer_head.h:309 [inline] udf_tread+0xe1/0x130 fs/udf/misc.c:44 udf_read_tagged+0x40/0x4c0 fs/udf/misc.c:210 udf_check_anchor_block+0x18a/0x590 fs/udf/super.c:1816 udf_scan_anchors+0x3b9/0x530 fs/udf/super.c:1895 udf_find_anchor fs/udf/super.c:1913 [inline] udf_load_vrs+0x5a1/0xa90 fs/udf/super.c:1978 udf_fill_super+0x715/0x1680 fs/udf/super.c:2170 mount_bdev+0x2b3/0x360 fs/super.c:1134 mount_fs+0x92/0x2a0 fs/super.c:1237 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2549 [inline] do_mount+0xe53/0x2a00 fs/namespace.c:2879 SYSC_mount fs/namespace.c:3095 [inline] SyS_mount+0xa8/0x120 fs/namespace.c:3072 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x466459 RSP: 002b:00007f1e136d5188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459 RDX: 0000000020000000 RSI: 0000000020000180 RDI: 0000000020000380 RBP: 00000000004bf9fb R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007fff44b587df R14: 00007f1e136d5300 R15: 0000000000022000 Code: 29 00 e9 2c fe ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 65 48 8b 04 25 80 df 01 00 48 85 c0 74 1a 65 8b 15 2b bb ac 7e <81> e2 00 01 1f 00 75 0b 8b 90 58 13 00 00 83 fa 01 74 01 c3 48