netlink: 3 bytes leftover after parsing attributes in process `syz-executor2'. INFO: task syz-executor7:16476 blocked for more than 120 seconds. Not tainted 4.9.108-gb7d377b #50 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor7 D29464 16476 3835 0x00000004 ffff8801d8a9b000 0000000000000000 ffff8801b6184000 ffffffff84629800 ffff8801db221c18 ffff880190ae7aa0 ffffffff839e8aed 1ffff1003215cf48 ffffffff85542240 0000000041b58ab3 00ffffff843c23b8 ffff8801db2224e8 Call Trace: [] schedule+0x7f/0x1b0 kernel/sched/core.c:3557 [] schedule_timeout+0x861/0xf70 kernel/time/timer.c:1768 [] io_schedule_timeout+0x1ba/0x390 kernel/sched/core.c:5180 [] do_wait_for_common kernel/sched/completion.c:75 [inline] [] __wait_for_common kernel/sched/completion.c:93 [inline] [] wait_for_common_io kernel/sched/completion.c:107 [inline] [] wait_for_completion_io+0x203/0x2e0 kernel/sched/completion.c:155 [] submit_bio_wait+0x112/0x180 block/bio.c:885 [] blkdev_issue_flush+0x152/0x220 block/blk-flush.c:518 [] blkdev_fsync+0x85/0xb0 fs/block_dev.c:378 [] vfs_fsync_range+0x10c/0x260 fs/sync.c:195 [] vfs_fsync fs/sync.c:209 [inline] [] do_fsync+0x42/0xb0 fs/sync.c:219 [] SYSC_fdatasync fs/sync.c:233 [inline] [] SyS_fdatasync+0x19/0x20 fs/sync.c:231 [] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282 [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb Showing all locks held in the system: 2 locks held by khungtaskd/519: #0: (rcu_read_lock){......}, at: [] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline] #0: (rcu_read_lock){......}, at: [] watchdog+0x11c/0xa20 kernel/hung_task.c:239 #1: (tasklist_lock){.+.+..}, at: [] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336 2 locks held by getty/3777: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2133 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 519 Comm: khungtaskd Not tainted 4.9.108-gb7d377b #50 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ffff8801d8b1fd08 ffffffff81eb3e29 0000000000000000 0000000000000000 0000000000000000 0000000000000001 ffffffff810b96a0 ffff8801d8b1fd40 ffffffff81ebf127 0000000000000000 0000000000000000 0000000000000003 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x128 lib/dump_stack.c:51 [] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99 [] nmi_trigger_cpumask_backtrace+0x12a/0x14f lib/nmi_backtrace.c:60 [] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37 [] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline] [] check_hung_task kernel/hung_task.c:125 [inline] [] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline] [] watchdog+0x6b4/0xa20 kernel/hung_task.c:239 [] kthread+0x26d/0x300 kernel/kthread.c:211 [] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at pc 0xffffffff839f85f6