WTF: patch "[PATCH] drm: add __user attribute to ptr_to_compat()" was seriously submitted to be applied to the 5.0-stable tree?

The patch below was submitted to be applied to the 5.0-stable tree.

I fail to see how this patch meets the stable kernel rules as found at Documentation/process/stable-kernel-rules.rst.

I could be totally wrong, and if so, please respond to <[email protected]> and let me know why this patch should be applied. Otherwise, it is now dropped from my patch queues, never to be seen again.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From e552f0851070fe4975d610a99910be4e9bf5d7bd Mon Sep 17 00:00:00 2001
From: Ben Dooks <[email protected]>
Date: Fri, 1 Mar 2019 12:00:46 +0000
Subject: [PATCH] drm: add __user attribute to ptr_to_compat()

The ptr_to_compat() call takes a "void __user *", so cast the compat drm calls that use it to avoid the following warnings from sparse:

drivers/gpu/drm/drm_ioc32.c:188:39: warning: incorrect type in argument 1 (different address spaces)
drivers/gpu/drm/drm_ioc32.c:188:39: expected void [noderef] <asn:1>*uptr
drivers/gpu/drm/drm_ioc32.c:188:39: got void *[addressable] [assigned] handle
drivers/gpu/drm/drm_ioc32.c:529:41: warning: incorrect type in argument 1 (different address spaces)
drivers/gpu/drm/drm_ioc32.c:529:41: expected void [noderef] <asn:1>*uptr
drivers/gpu/drm/drm_ioc32.c:529:41: got void *[addressable] [assigned] handle

index 67b1fca39aa6..0e3043e08c69 100644
@@ -185,7 +185,7 @@ static int compat_drm_getmap(struct file *file, unsigned int cmd,
 	m32.size = map.size;
 	m32.type = map.type;
 	m32.flags = map.flags;
-	m32.handle = ptr_to_compat(map.handle);
+	m32.handle = ptr_to_compat((void __user *)map.handle);
 	m32.mtrr = map.mtrr;
 	if (copy_to_user(argp, &m32, sizeof(m32)))
 		return -EFAULT;

@@ -216,7 +216,7 @@ static int compat_drm_addmap(struct file *file, unsigned int cmd,
 
 	m32.offset = map.offset;
 	m32.mtrr = map.mtrr;
-	m32.handle = ptr_to_compat(map.handle);
+	m32.handle = ptr_to_compat((void __user *)map.handle);
 	if (map.handle != compat_ptr(m32.handle))
 		pr_err_ratelimited("compat_drm_addmap truncated handle %p for type %d offset %x\n",
 				   map.handle, m32.type, m32.offset);

@@ -526,7 +526,7 @@ static int compat_drm_getsareactx(struct file *file, unsigned int cmd,
 	if (err)
 		return err;
 
-	req32.handle = ptr_to_compat(req.handle);
+	req32.handle = ptr_to_compat((void __user *)req.handle);
 	if (copy_to_user(argp, &req32, sizeof(req32)))
 		return -EFAULT;