INFO: task syz-executor.0:14369 blocked for more than 140 seconds. Not tainted 4.19.211-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D30000 14369 8157 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x887/0x2040 kernel/sched/core.c:3517 schedule+0x8d/0x1b0 kernel/sched/core.c:3561 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline] rwsem_down_read_failed+0x20a/0x390 kernel/locking/rwsem-xadd.c:309 call_rwsem_down_read_failed+0x14/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] down_read+0x44/0x80 kernel/locking/rwsem.c:26 __get_super.part.0+0x209/0x2e0 fs/super.c:698 __get_super include/linux/spinlock.h:329 [inline] get_super+0x2b/0x50 fs/super.c:727 fsync_bdev+0x14/0xc0 fs/block_dev.c:483 blkdev_flushbuf block/ioctl.c:436 [inline] blkdev_ioctl+0x912/0x1a80 block/ioctl.c:521 block_ioctl+0xe9/0x130 fs/block_dev.c:1906 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcdb/0x12e0 fs/ioctl.c:688 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fc8efd633c9 Code: Bad RIP value. RSP: 002b:00007fc8ee6b7168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fc8efe76050 RCX: 00007fc8efd633c9 RDX: 0000000000000000 RSI: 0000000000001261 RDI: 0000000000000003 RBP: 00007fc8efdbe33f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd2dada1ef R14: 00007fc8ee6b7300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/1492: #0: 00000000adf132e2 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441 1 lock held by in:imklog/7838: #0: 000000004c37c987 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767 2 locks held by agetty/8053: #0: 00000000ca15f672 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 000000005dbafbf7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x217/0x1950 drivers/tty/n_tty.c:2154 2 locks held by syz-executor.0/14367: 1 lock held by syz-executor.0/14369: #0: 00000000b8428154 (&type->s_umount_key#70){++++}, at: __get_super.part.0+0x209/0x2e0 fs/super.c:698 2 locks held by syz-executor.0/14876: #0: 00000000a2b2cd4b (&bdev->bd_fsfreeze_mutex){+.+.}, at: mount_bdev+0x90/0x3b0 fs/super.c:1125 #1: 00000000b8428154 (&type->s_umount_key#70){++++}, at: grab_super+0xa2/0x350 fs/super.c:383 1 lock held by syz-executor.0/14877: #0: 00000000b8428154 (&type->s_umount_key#70){++++}, at: __get_super.part.0+0x209/0x2e0 fs/super.c:698 1 lock held by syz-executor.1/16246: #0: 0000000072a27656 (&bdev->bd_mutex){+.+.}, at: blkdev_put+0x30/0x520 fs/block_dev.c:1839 1 lock held by syz-executor.1/16253: 2 locks held by syz-executor.3/16255: #0: 0000000072a27656 (&bdev->bd_mutex){+.+.}, at: blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 #1: 000000006d9419f7 (&type->s_umount_key#70){++++}, at: __get_super.part.0+0x209/0x2e0 fs/super.c:698 1 lock held by systemd-udevd/16250: #0: 0000000072a27656 (&bdev->bd_mutex){+.+.}, at: __blkdev_get+0x1d0/0x1480 fs/block_dev.c:1478 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1492 Comm: khungtaskd Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x991/0xe60 kernel/hung_task.c:287 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 10 Comm: rcu_preempt Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 RIP: 0010:register_lock_class+0x9e/0x11c0 kernel/locking/lockdep.c:747 Code: 98 00 00 00 31 c9 48 c1 ea 03 0f b6 14 02 4c 89 d0 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 5a 06 00 00 44 8b 05 a2 aa d9 0b <45> 85 c0 75 3d 48 c7 c0 80 82 f1 89 48 ba 00 00 00 00 00 fc ff df RSP: 0018:ffff8880b5a67908 EFLAGS: 00000097 RAX: 0000000000000003 RBX: ffff8880b5a67ce8 RCX: 0000000000000000 RDX: 0000000000000004 RSI: 0000000000000000 RDI: ffff8880b5a67ce8 RBP: 0000000000000000 R08: 0000000000000000 R09: 1ffff11016b4cf29 R10: ffffffff8d243760 R11: 0000000000000000 R12: 0000000000000001 R13: ffff8880b5a4e280 R14: 1ffff11016b4cf29 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe57ccc6020 CR3: 00000000a1293000 CR4: 00000000003406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_acquire+0x17d/0x3ff0 kernel/locking/lockdep.c:3304 lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908 del_timer_sync+0xab/0x270 kernel/time/timer.c:1295 schedule_timeout+0x4d7/0xfe0 kernel/time/timer.c:1819 rcu_gp_kthread+0xdad/0x21c0 kernel/rcu/tree.c:2202 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415