INFO: task syz.0.788:5767 blocked for more than 444 seconds.
      Tainted: G             L      syzkaller #0
      Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.788       state:D stack:0     pid:5767  tgid:5766  ppid:3244   task_flags:0x40044c flags:0x00000002
Call Trace:
[<ffffffff8639c964>] context_switch kernel/sched/core.c:5260 [inline]
[<ffffffff8639c964>] __schedule+0xf10/0x4098 kernel/sched/core.c:6867
[<ffffffff8639fba0>] __schedule_loop kernel/sched/core.c:6949 [inline]
[<ffffffff8639fba0>] schedule+0xb4/0x334 kernel/sched/core.c:6964
[<ffffffff8639ff22>] schedule_preempt_disabled+0x16/0x28 kernel/sched/core.c:7021
[<ffffffff863ab03e>] rwsem_down_read_slowpath+0x4ca/0x954 kernel/locking/rwsem.c:1086
[<ffffffff863ab5a8>] __down_read_common kernel/locking/rwsem.c:1261 [inline]
[<ffffffff863ab5a8>] __down_read kernel/locking/rwsem.c:1274 [inline]
[<ffffffff863ab5a8>] down_read+0xe0/0x454 kernel/locking/rwsem.c:1539
[<ffffffff8015af96>] mmap_read_lock include/linux/mmap_lock.h:391 [inline]
[<ffffffff8015af96>] exit_mm kernel/exit.c:557 [inline]
[<ffffffff8015af96>] do_exit+0x69a/0x2828 kernel/exit.c:959
[<ffffffff8015d64e>] do_group_exit+0xca/0x258 kernel/exit.c:1112
[<ffffffff801951fa>] get_signal+0x1f7e/0x224c kernel/signal.c:3034
[<ffffffff800726f0>] arch_do_signal_or_restart+0xca0/0x1ddc arch/riscv/kernel/signal.c:534
[<ffffffff803c0aee>] __exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
[<ffffffff803c0aee>] exit_to_user_mode_loop+0x8e/0x874 kernel/entry/common.c:75
[<ffffffff86391c9a>] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
[<ffffffff86391c9a>] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
[<ffffffff86391c9a>] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
[<ffffffff86391c9a>] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
[<ffffffff86391c9a>] do_trap_ecall_u+0x462/0x58c arch/riscv/kernel/traps.c:359
[<ffffffff863bb61e>] handle_exception+0x15e/0x16a arch/riscv/kernel/entry.S:232

Showing all locks held in the system:
1 lock held by kthreadd/2:
1 lock held by khungtaskd/33:
 #0: ffffffff885ec160 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2a/0x1a8 kernel/locking/lockdep.c:6771