On Tuesday, 23 January 2024 19:14:17 CST Greg Kroah-Hartman wrote:

On Tue, Jan 23, 2024 at 06:40:22PM -0600, Elizabeth Figura wrote:

quoted

+static int ntsync_create_sem(struct ntsync_device *dev, void __user
*argp)
+{
+	struct ntsync_sem_args __user *user_args = argp;
+	struct ntsync_sem_args args;
+	struct ntsync_obj *sem;
+	__u32 id;
+	int ret;
+
+	if (copy_from_user(&args, argp, sizeof(args)))
+		return -EFAULT;
+
+	if (args.count > args.max)
+		return -EINVAL;

No bounds checking on count or max?

What's the relationship between count and max?  

Indeed, no bounds checking. The counter is just the semaphore's internal value 
and has no meaning other than that.

It's basically like an EFD_SEMAPHORE, except that the maximum is configurable 
rather than always being 2**64-2.

Some sort of real
documentation is needed here, the changelog needs to explain this.  Or
somewhere, but as-is, this patch series is pretty unreviewable as I
can't figure out how to review it because I don't know what it wants to
do.

There is some comprehensive documentation in the series, but for ease of 
review I will try to write a basic description of the API in each relevant 
patch in v2.