netlink: 8 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor.5'. INFO: task syz-executor.5:2096 blocked for more than 140 seconds. Not tainted 4.9.186+ #10 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D24792 2096 1 0x00000004 0000000000000087 ffff8801d16eaf80 ffff8801d11a9600 ffff8801db621000 ffff8801d32cdf00 ffff8801db621018 ffff8801ada276a8 ffffffff8280c5ee 0000000000000246 ffffffff831f3408 00ff8801d16eb828 ffff8801db6218f0 Call Trace: [<00000000c028362f>] schedule+0x92/0x1c0 kernel/sched/core.c:3546 [<0000000031174425>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3579 [<0000000047d5b460>] __mutex_lock_common kernel/locking/mutex.c:582 [inline] [<0000000047d5b460>] mutex_lock_nested+0x38d/0x920 kernel/locking/mutex.c:621 [<000000009794cac5>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 [<0000000012887c5a>] blkdev_get+0x2e8/0x920 fs/block_dev.c:1424 [<000000004fc9b04c>] blkdev_open+0x1aa/0x250 fs/block_dev.c:1579 [<000000001a51a9fe>] do_dentry_open+0x422/0xd20 fs/open.c:772 [<0000000043c72dce>] vfs_open+0x105/0x230 fs/open.c:885 [<00000000899ccefc>] do_last fs/namei.c:3457 [inline] [<00000000899ccefc>] path_openat+0xbf5/0x2f60 fs/namei.c:3581 [<000000006005f9f6>] do_filp_open+0x1a1/0x280 fs/namei.c:3615 [<000000003c4a10cc>] do_sys_open+0x2f0/0x610 fs/open.c:1078 [<0000000044e3a749>] SYSC_open fs/open.c:1096 [inline] [<0000000044e3a749>] SyS_open+0x2d/0x40 fs/open.c:1091 [<00000000da709752>] do_syscall_64+0x1ad/0x5c0 arch/x86/entry/common.c:288 [<00000000862c5b49>] 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: [<000000004aa0cdba>] check_hung_uninterruptible_tasks kernel/hung_task.c:169 [inline] #0: (rcu_read_lock){......}, at: [<000000004aa0cdba>] watchdog+0x14b/0xaf0 kernel/hung_task.c:263 #1: (tasklist_lock){.+.+..}, at: [<0000000034923fab>] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4336 1 lock held by rsyslogd/1900: #0: (&f->f_pos_lock){+.+.+.}, at: [<0000000080fc2f1f>] __fdget_pos+0xa8/0xd0 fs/file.c:782 2 locks held by getty/2027: #0: (&tty->ldisc_sem){++++++}, at: [<000000006966fecf>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+...}, at: [<000000008b4ecf69>] n_tty_read+0x1fe/0x1820 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.5/2096: #0: (&bdev->bd_mutex){+.+.+.}, at: [<000000009794cac5>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 2 locks held by syz-executor.2/2111: #0: (&bdev->bd_mutex){+.+.+.}, at: [<000000009794cac5>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 #1: (loop_index_mutex){+.+.+.}, at: [<00000000b5bc4d46>] lo_open+0x1d/0xb0 drivers/block/loop.c:1621 2 locks held by syz-executor.1/8099: #0: (loop_index_mutex){+.+.+.}, at: [<0000000088029ff0>] loop_control_ioctl+0x7a/0x320 drivers/block/loop.c:1973 #1: (&lo->lo_ctl_mutex#2){+.+.+.}, at: [<000000006756d26e>] loop_control_ioctl+0x17f/0x320 drivers/block/loop.c:1987 1 lock held by syz-executor.1/8116: #0: (loop_index_mutex){+.+.+.}, at: [<0000000088029ff0>] loop_control_ioctl+0x7a/0x320 drivers/block/loop.c:1973 2 locks held by syz-executor.0/8109: #0: (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<000000007bf3f39c>] lo_ioctl+0x8e/0x1b10 drivers/block/loop.c:1404 #1: (&bdev->bd_mutex){+.+.+.}, at: [<000000001decf918>] blkdev_reread_part+0x1f/0x40 block/ioctl.c:189 1 lock held by syz-executor.0/8122: #0: (&bdev->bd_mutex){+.+.+.}, at: [<000000009794cac5>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 1 lock held by syz-executor.4/8108: #0: (loop_index_mutex){+.+.+.}, at: [<0000000088029ff0>] loop_control_ioctl+0x7a/0x320 drivers/block/loop.c:1973 1 lock held by syz-executor.4/8119: #0: (loop_index_mutex){+.+.+.}, at: [<0000000088029ff0>] loop_control_ioctl+0x7a/0x320 drivers/block/loop.c:1973 2 locks held by blkid/8105: #0: (&bdev->bd_mutex){+.+.+.}, at: [<0000000034b3ee17>] __blkdev_put+0xbb/0x840 fs/block_dev.c:1587 #1: (loop_index_mutex){+.+.+.}, at: [<000000005003d02e>] lo_release+0x20/0x1b0 drivers/block/loop.c:1663 1 lock held by syz-executor.3/8111: #0: (loop_index_mutex){+.+.+.}, at: [<0000000088029ff0>] loop_control_ioctl+0x7a/0x320 drivers/block/loop.c:1973 1 lock held by syz-executor.3/8118: #0: (loop_index_mutex){+.+.+.}, at: [<0000000088029ff0>] loop_control_ioctl+0x7a/0x320 drivers/block/loop.c:1973 2 locks held by blkid/8112: #0: (&bdev->bd_mutex){+.+.+.}, at: [<000000009794cac5>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 #1: (loop_index_mutex){+.+.+.}, at: [<00000000b5bc4d46>] lo_open+0x1d/0xb0 drivers/block/loop.c:1621 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 24 Comm: khungtaskd Not tainted 4.9.186+ #10 ffff8801d98d7cc8 ffffffff81b5a0b1 0000000000000001 0000000000000000 0000000000000001 ffffffff81099a01 dffffc0000000000 ffff8801d98d7d00 ffffffff81b6534c 0000000000000001 0000000000000000 0000000000000001 Call Trace: [<00000000c78b36ea>] __dump_stack lib/dump_stack.c:15 [inline] [<00000000c78b36ea>] dump_stack+0xc1/0x120 lib/dump_stack.c:51 [<00000000e1b745ea>] nmi_cpu_backtrace.cold+0x47/0x87 lib/nmi_backtrace.c:99 [<000000003e0f8927>] nmi_trigger_cpumask_backtrace+0x124/0x155 lib/nmi_backtrace.c:60 [<00000000ad467b3f>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37 [<00000000156b16fe>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline] [<00000000156b16fe>] check_hung_task kernel/hung_task.c:126 [inline] [<00000000156b16fe>] check_hung_uninterruptible_tasks kernel/hung_task.c:183 [inline] [<00000000156b16fe>] watchdog+0x670/0xaf0 kernel/hung_task.c:263 [<00000000b718d60e>] kthread+0x278/0x310 kernel/kthread.c:211 [<00000000901d3848>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:375 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff8281b741