loop0: p1 size 2 extends beyond EOD, truncated loop0: p4 start 1854537728 is beyond EOD, truncated INFO: task syz-executor.2:5078 blocked for more than 140 seconds. Not tainted 4.9.170+ #48 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28280 5078 2124 0x80000002 ffff8801c73f2f80 0000000000000000 ffff8801db721000 ffff8801c6a30000 ffff8801db721018 ffff8801c6dd76b8 ffffffff82801a4e 0000000041b58ab3 ffffffff82e28708 00ffffff811ffe30 ffff8801db7218f0 1ffff10038dbaec6 Call Trace: [<000000008d2804c0>] schedule+0x92/0x1c0 kernel/sched/core.c:3546 [<00000000ada34aed>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3579 [<00000000303a6e59>] __mutex_lock_common kernel/locking/mutex.c:582 [inline] [<00000000303a6e59>] mutex_lock_nested+0x38d/0x920 kernel/locking/mutex.c:621 [<000000002d949db2>] lo_release+0x1e/0x1b0 drivers/block/loop.c:1664 [<000000005f597a18>] __blkdev_put+0x461/0x840 fs/block_dev.c:1606 [<0000000052aefa90>] blkdev_put+0x88/0x560 fs/block_dev.c:1671 [<00000000fd48ed32>] blkdev_close+0x8b/0xb0 fs/block_dev.c:1678 [<00000000e34a3a27>] __fput+0x274/0x720 fs/file_table.c:208 [<00000000ffd0e06d>] ____fput+0x16/0x20 fs/file_table.c:244 [<000000006c995908>] task_work_run+0x108/0x180 kernel/task_work.c:116 [<000000001fc82054>] exit_task_work include/linux/task_work.h:21 [inline] [<000000001fc82054>] do_exit+0x78b/0x2aa0 kernel/exit.c:841 [<000000001357c6e2>] do_group_exit+0x111/0x300 kernel/exit.c:945 [<00000000f87b2921>] get_signal+0x348/0x1aa0 kernel/signal.c:2380 [<00000000f12a9150>] do_signal+0x9c/0x1920 arch/x86/kernel/signal.c:807 [<000000008cd0c84c>] exit_to_usermode_loop+0x11c/0x160 arch/x86/entry/common.c:158 [<00000000ee7adb1a>] prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline] [<00000000ee7adb1a>] syscall_return_slowpath arch/x86/entry/common.c:263 [inline] [<00000000ee7adb1a>] do_syscall_64+0x3f7/0x570 arch/x86/entry/common.c:290 [<00000000ee80084f>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb Showing all locks held in the system: 2 locks held by khungtaskd/24: #0: (rcu_read_lock){......}, at: [<0000000048e50c01>] check_hung_uninterruptible_tasks kernel/hung_task.c:169 [inline] #0: (rcu_read_lock){......}, at: [<0000000048e50c01>] watchdog+0x14b/0xaf0 kernel/hung_task.c:263 #1: (tasklist_lock){.+.+..}, at: [<000000004f7505e0>] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4339 2 locks held by getty/2026: #0: (&tty->ldisc_sem){++++++}, at: [<0000000063b53f8a>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+...}, at: [<000000000125a631>] n_tty_read+0x1fe/0x1820 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.2/5078: #0: (&bdev->bd_mutex){+.+.+.}, at: [<0000000067f0f8fc>] __blkdev_put+0xbb/0x840 fs/block_dev.c:1587 #1: (loop_index_mutex){+.+.+.}, at: [<000000002d949db2>] lo_release+0x1e/0x1b0 drivers/block/loop.c:1664 1 lock held by syz-executor.5/26397: #0: (&bdev->bd_mutex){+.+.+.}, at: [<0000000029c7b546>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 2 locks held by syz-executor.4/27099: #0: (&bdev->bd_mutex){+.+.+.}, at: [<0000000029c7b546>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 #1: (loop_index_mutex){+.+.+.}, at: [<00000000a5282503>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622 2 locks held by syz-executor.0/30916: #0: (loop_ctl_mutex/1){+.+.+.}, at: [<000000007d9c0cd9>] lo_ioctl+0x85/0x1a10 drivers/block/loop.c:1405 #1: (&bdev->bd_mutex){+.+.+.}, at: [<00000000f164a91f>] blkdev_reread_part+0x1f/0x40 block/ioctl.c:189 1 lock held by syz-executor.2/30947: #0: (loop_ctl_mutex/1){+.+.+.}, at: [<000000007d9c0cd9>] lo_ioctl+0x85/0x1a10 drivers/block/loop.c:1405 3 locks held by blkid/30942: #0: (&bdev->bd_mutex){+.+.+.}, at: [<0000000067f0f8fc>] __blkdev_put+0xbb/0x840 fs/block_dev.c:1587 #1: (loop_index_mutex){+.+.+.}, at: [<000000002d949db2>] lo_release+0x1e/0x1b0 drivers/block/loop.c:1664 #2: (loop_ctl_mutex#2){+.+.+.}, at: [<00000000640dfe39>] __lo_release drivers/block/loop.c:1642 [inline] #2: (loop_ctl_mutex#2){+.+.+.}, at: [<00000000640dfe39>] lo_release+0x84/0x1b0 drivers/block/loop.c:1665 2 locks held by blkid/30943: #0: (&bdev->bd_mutex){+.+.+.}, at: [<0000000029c7b546>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 #1: (loop_index_mutex){+.+.+.}, at: [<00000000a5282503>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622 1 lock held by blkid/30958: #0: (&bdev->bd_mutex){+.+.+.}, at: [<0000000029c7b546>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 24 Comm: khungtaskd Not tainted 4.9.170+ #48 ffff8801d98d7cc8 ffffffff81b4fb21 0000000000000001 0000000000000000 0000000000000001 ffffffff81097401 dffffc0000000000 ffff8801d98d7d00 ffffffff81b5adbc 0000000000000001 0000000000000000 0000000000000001 Call Trace: [<0000000050f697d9>] __dump_stack lib/dump_stack.c:15 [inline] [<0000000050f697d9>] dump_stack+0xc1/0x120 lib/dump_stack.c:51 [<00000000d00c2721>] nmi_cpu_backtrace.cold+0x47/0x87 lib/nmi_backtrace.c:99 [<00000000a790d1ce>] nmi_trigger_cpumask_backtrace+0x124/0x155 lib/nmi_backtrace.c:60 [<000000005df02ebc>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37 [<000000007a8e3f5f>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline] [<000000007a8e3f5f>] check_hung_task kernel/hung_task.c:126 [inline] [<000000007a8e3f5f>] check_hung_uninterruptible_tasks kernel/hung_task.c:183 [inline] [<000000007a8e3f5f>] watchdog+0x670/0xaf0 kernel/hung_task.c:263 [<0000000048d39dc7>] kthread+0x278/0x310 kernel/kthread.c:211 [<00000000b322abfd>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff82810ac2