device syz_tun left promiscuous mode device syz_tun entered promiscuous mode device syz_tun left promiscuous mode device syz_tun entered promiscuous mode device syz_tun left promiscuous mode INFO: task syz-executor4:15115 blocked for more than 120 seconds. Not tainted 4.9.107-gdb2c520 #49 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D28928 15115 13170 0x00000004 ffff8801be8bb000 ffff8801c50b2f40 ffff8801c50b3480 ffff880199af3000 ffff8801db221c18 ffff88019a3cf890 ffffffff839e8c1d 1ffff10033479f06 ffffffff8555e978 0000000041b58ab3 00ffffff843c2388 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 [] io_schedule include/linux/sched.h:460 [inline] [] bit_wait_io+0x19/0xa0 kernel/sched/wait.c:582 [] __wait_on_bit_lock+0xce/0x1c0 kernel/sched/wait.c:421 [] __lock_page+0xff/0x160 mm/filemap.c:934 [] lock_page include/linux/pagemap.h:454 [inline] [] pagecache_get_page+0x409/0x720 mm/filemap.c:1216 [] find_lock_page include/linux/pagemap.h:284 [inline] [] truncate_inode_pages_range+0xca6/0x1290 mm/truncate.c:320 [] blkdev_fallocate+0x21d/0x440 fs/block_dev.c:1817 [] vfs_fallocate+0x359/0x600 fs/open.c:329 [] SYSC_fallocate fs/open.c:352 [inline] [] SyS_fallocate+0x53/0x90 fs/open.c:346 [] 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/3750: #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 1 lock held by syz-executor4/15115: #0: (sb_writers){.+.+.+}, at: [] sb_start_write include/linux/fs.h:1573 [inline] #0: (sb_writers){.+.+.+}, at: [] vfs_fallocate+0x2fb/0x600 fs/open.c:328 1 lock held by syz-executor4/15166: #0: (sb_writers){.+.+.+}, at: [] sb_start_write include/linux/fs.h:1573 [inline] #0: (sb_writers){.+.+.+}, at: [] vfs_fallocate+0x2fb/0x600 fs/open.c:328 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 519 Comm: khungtaskd Not tainted 4.9.107-gdb2c520 #49 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ffff8801d85cfd08 ffffffff81eb3da9 0000000000000000 0000000000000000 0000000000000000 0000000000000001 ffffffff810b96a0 ffff8801d85cfd40 ffffffff81ebf0a7 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 0xffffffff839f8726