Commit a957b612 authored by Jens Axboe's avatar Jens Axboe
Browse files

block: fix error in handling dead task for ioprio setting 



Don't combine the task exiting and "already have io_context" case, we
need to just abort if the task is marked as dead. Return -ESRCH, which
is the documented value for ioprio_set() if the specified task could not
be found.

Reported-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Reported-by: default avatar <syzbot+8836466a79f4175961b0@syzkaller.appspotmail.com>
Fixes: 5fc11eeb ("block: open code create_task_io_context in set_task_ioprio")
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 518579a9

block/blk-ioc.c

+8 −2
Original line number Diff line number Diff line
@@ -279,7 +279,12 @@ int set_task_ioprio(struct task_struct *task, int ioprio) 
			return -ENOMEM;



		task_lock(task);

		if (task->io_context || (task->flags & PF_EXITING)) {

		if (task->flags & PF_EXITING) {

			err = -ESRCH;

			kmem_cache_free(iocontext_cachep, ioc);

			goto out;

		}

		if (task->io_context) {

			kmem_cache_free(iocontext_cachep, ioc);

			ioc = task->io_context;

		} else {
@@ -287,8 +292,9 @@ int set_task_ioprio(struct task_struct *task, int ioprio) 
		}

	}

	task->io_context->ioprio = ioprio;

out:

	task_unlock(task);

	return 0;

	return err;

}

EXPORT_SYMBOL_GPL(set_task_ioprio);