INFO: task syz-executor.2:9883 blocked for more than 140 seconds. Not tainted 4.14.292-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D30296 9883 7976 0x00000004 Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline] rwsem_down_read_failed+0x1e6/0x350 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:66 [inline] down_read+0x44/0x80 kernel/locking/rwsem.c:26 __get_super.part.0+0x271/0x390 fs/super.c:678 __get_super include/linux/spinlock.h:317 [inline] get_super+0x2b/0x50 fs/super.c:707 fsync_bdev+0x14/0xc0 fs/block_dev.c:495 blkdev_flushbuf block/ioctl.c:430 [inline] blkdev_ioctl+0x883/0x1830 block/ioctl.c:514 block_ioctl+0xd9/0x120 fs/block_dev.c:1893 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f2605f4f3c9 RSP: 002b:00007f26048a3168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f2606062050 RCX: 00007f2605f4f3c9 RDX: 0000000000000000 RSI: 0000000000001261 RDI: 0000000000000003 RBP: 00007f2605faa33f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffa35dfcaf R14: 00007f26048a3300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/1534: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 1 lock held by syz-executor.2/9883: #0: (&type->s_umount_key#50){++++}, at: [] __get_super.part.0+0x271/0x390 fs/super.c:678 2 locks held by syz-executor.2/10226: #0: (&bdev->bd_fsfreeze_mutex){+.+.}, at: [] mount_bdev+0x71/0x360 fs/super.c:1101 #1: (&type->s_umount_key#50){++++}, at: [] grab_super+0x55/0x140 fs/super.c:373 1 lock held by syz-executor.2/10228: #0: (&type->s_umount_key#50){++++}, at: [] __get_super.part.0+0x271/0x390 fs/super.c:678 1 lock held by syz-executor.5/14040: #0: (rcu_preempt_state.barrier_mutex){+.+.}, at: [] _rcu_barrier+0x56/0x3b0 kernel/rcu/tree.c:3546 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1534 Comm: khungtaskd Not tainted 4.14.292-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 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: 14040 Comm: syz-executor.5 Not tainted 4.14.292-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 task: ffff88806b816340 task.stack: ffff888065ce8000 RIP: 0010:mm_counter include/linux/mm.h:1549 [inline] RIP: 0010:zap_pte_range mm/memory.c:1374 [inline] RIP: 0010:zap_pmd_range mm/memory.c:1479 [inline] RIP: 0010:zap_pud_range mm/memory.c:1508 [inline] RIP: 0010:zap_p4d_range mm/memory.c:1529 [inline] RIP: 0010:unmap_page_range+0xeb1/0x1d90 mm/memory.c:1550 RSP: 0018:ffff888065cef7c8 EFLAGS: 00000246 RAX: ffffea0002a84d80 RBX: dffffc0000000000 RCX: ffff888065cef9d0 RDX: 1ffffd40005509b1 RSI: ffff888065cef9d0 RDI: ffffea0002a84d88 RBP: ffffea0002a84d80 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: ffff88806b816340 R12: ffffea0002a84da0 R13: ffff8880a411cba0 R14: 00007feae8775000 R15: dead000000000100 FS: 0000000000000000(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020319000 CR3: 0000000008e6a000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: unmap_single_vma+0x147/0x2b0 mm/memory.c:1595 unmap_vmas+0x9d/0x160 mm/memory.c:1625 exit_mmap+0x270/0x4d0 mm/mmap.c:3073 __mmput kernel/fork.c:931 [inline] mmput kernel/fork.c:952 [inline] mmput+0xfa/0x420 kernel/fork.c:947 exit_mm kernel/exit.c:548 [inline] do_exit+0x984/0x2850 kernel/exit.c:855 do_group_exit+0x100/0x2e0 kernel/exit.c:965 get_signal+0x38d/0x1ca0 kernel/signal.c:2412 do_signal+0x7c/0x1550 arch/x86/kernel/signal.c:792 exit_to_usermode_loop+0x160/0x200 arch/x86/entry/common.c:160 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7feae90fb3c9 RSP: 002b:00007feae7a70168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: 0000000000000044 RBX: 00007feae920df80 RCX: 00007feae90fb3c9 RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000003 RBP: 00007feae915633f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe1d15fa6f R14: 00007feae7a70300 R15: 0000000000022000 Code: 00 48 89 84 24 90 00 00 00 e8 ac b3 e0 ff 48 8b 84 24 90 00 00 00 48 8d 78 08 48 89 fa 48 c1 ea 03 80 3c 1a 00 0f 85 52 0d 00 00 40 08 01 41 bf 01 00 00 00 75 3d e8 7e b3 e0 ff 48 8b 45 20