syzbot has found a reproducer for the following issue on: HEAD commit: 9317f948 Add linux-next specific files for 20201215 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=151add97500000 kernel config: https://syzkaller.appspot.com/x/.config?x=5c81cc44aa25b5b3 dashboard link: https://syzkaller.appspot.com/bug?extid=61cb1d04bf13f0c631b1 compiler: gcc (GCC) 10.1.0-syz 20200507 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=177df703500000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1342f30f500000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+61cb1d04bf13f0c631b1@xxxxxxxxxxxxxxxxxxxxxxxxx INFO: task syz-executor656:8498 can't die for more than 143 seconds. task:syz-executor656 state:R running task stack:27904 pid: 8498 ppid: 8493 flags:0x00004006 Call Trace: Showing all locks held in the system: 1 lock held by khungtaskd/1647: #0: ffffffff8b78f920 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x28c kernel/locking/lockdep.c:6254 1 lock held by in:imklog/8185: #0: ffff88801ad9e0f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:923 3 locks held by syz-executor656/8498: ============================================= Kernel panic - not syncing: hung_task: blocked tasks CPU: 0 PID: 1647 Comm: khungtaskd Not tainted 5.10.0-next-20201215-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 panic+0x343/0x77f kernel/panic.c:231 check_hung_uninterruptible_tasks kernel/hung_task.c:257 [inline] watchdog.cold+0x157/0x31d kernel/hung_task.c:338 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Kernel Offset: disabled Rebooting in 86400 seconds..
