[ OK ] Reached target Login Prompts. [ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Update UTMP about System Runlevel Changes. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.60' (ECDSA) to the list of known hosts. syzkaller login: [ 721.430005][ T1666] INFO: task syz-executor917:8513 can't die for more than 143 seconds. [ 721.438487][ T1666] task:syz-executor917 state:R running task stack:27912 pid: 8513 ppid: 8507 flags:0x00004006 [ 721.452570][ T1666] Call Trace: [ 721.455881][ T1666] ? find_inode+0x109/0x220 [ 721.461619][ T1666] ? find_inode+0x1b8/0x220 [ 721.466151][ T1666] ? iget5_locked+0xac/0x2d0 [ 721.473127][ T1666] ? iget5_locked+0xcc/0x2d0 [ 721.477768][ T1666] ? lock_downgrade+0x6d0/0x6d0 [ 721.483875][ T1666] ? rwlock_bug.part.0+0x90/0x90 [ 721.488848][ T1666] ? find_inode+0x109/0x220 [ 721.494600][ T1666] ? iget5_locked+0xac/0x2d0 [ 721.499219][ T1666] ? iget5_locked+0xac/0x2d0 [ 721.505063][ T1666] ? fuse_inode_eq+0x80/0x80 [ 721.509690][ T1666] ? fuse_iget+0x271/0x610 [ 721.515314][ T1666] ? fuse_change_attributes+0x610/0x610 [ 721.521651][ T1666] ? fuse_readdir_uncached+0x11e0/0x1730 [ 721.527333][ T1666] ? fuse_emit+0xc10/0xc10 [ 721.532937][ T1666] ? lockdep_hardirqs_on_prepare+0x420/0x420 [ 721.539022][ T1666] ? __mutex_lock+0x61b/0x1110 [ 721.545138][ T1666] ? lock_release+0x710/0x710 [ 721.550579][ T1666] ? fuse_readdir+0x842/0x1830 [ 721.555406][ T1666] ? down_read_killable+0x1a4/0x4a0 [ 721.562072][ T1666] ? down_read_interruptible+0x4a0/0x4a0 [ 721.567768][ T1666] ? security_file_permission+0x304/0x560 [ 721.575007][ T1666] ? iterate_dir+0x4eb/0x660 [ 721.579644][ T1666] ? __x64_sys_getdents+0x13a/0x2b0 [ 721.586069][ T1666] ? __ia32_sys_old_readdir+0x1c0/0x1c0 [ 721.592314][ T1666] ? filldir64+0x6a0/0x6a0 [ 721.596770][ T1666] ? syscall_enter_from_user_mode+0x1d/0x50 [ 721.605590][ T1666] ? do_syscall_64+0x2d/0x70 [ 721.611057][ T1666] ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 721.617267][ T1666] [ 721.617267][ T1666] Showing all locks held in the system: [ 721.626237][ T1666] 1 lock held by khungtaskd/1666: [ 721.633015][ T1666] #0: ffffffff8b793ae0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x28c [ 721.643646][ T1666] 1 lock held by in:imklog/8396: [ 721.648608][ T1666] #0: ffff888012ef0370 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 [ 721.658960][ T1666] 4 locks held by syz-executor917/8513: [ 721.665301][ T1666] [ 721.667640][ T1666] ============================================= [ 721.667640][ T1666] [ 721.677529][ T1666] Kernel panic - not syncing: hung_task: blocked tasks [ 721.684392][ T1666] CPU: 0 PID: 1666 Comm: khungtaskd Not tainted 5.10.0-next-20201218-syzkaller #0 [ 721.693607][ T1666] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 721.703702][ T1666] Call Trace: [ 721.706997][ T1666] dump_stack+0x107/0x163 [ 721.711351][ T1666] panic+0x343/0x77f [ 721.715263][ T1666] ? __warn_printk+0xf3/0xf3 [ 721.719875][ T1666] ? watchdog.cold+0x146/0x31d [ 721.724659][ T1666] watchdog.cold+0x157/0x31d [ 721.729262][ T1666] ? trace_sched_process_hang+0x2a0/0x2a0 [ 721.734999][ T1666] kthread+0x3b1/0x4a0 [ 721.739080][ T1666] ? kthread_create_worker_on_cpu+0xf0/0xf0 [ 721.744987][ T1666] ret_from_fork+0x1f/0x30 [ 721.750075][ T1666] Kernel Offset: disabled [ 721.754405][ T1666] Rebooting in 86400 seconds..