FAILED: patch "[PATCH] staging: vc04_services: shut up out-of-range warning" failed to apply to 4.14-stable tree

The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to [off-list ref].

thanks,

greg k-h

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

From 7ff4034e910fe00a90d985f0d05bacf60c162f02 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd@arndb.de>
Date: Mon, 27 Sep 2021 13:36:56 +0200
Subject: [PATCH] staging: vc04_services: shut up out-of-range warning

The comparison against SIZE_MAX produces a harmless warning on 64-bit
architectures:

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c:185:16: error: result of comparison of constant 419244183493398898 with expression of type 'unsigned int' is always false [-Werror,-Wtautological-constant-out-of-range-compare]
        if (num_pages > (SIZE_MAX - sizeof(struct pagelist) -
            ~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Shut up that warning by adding a cast to a longer type.

Fixes: ca641bae6da9 ("staging: vc04_services: prevent integer overflow in create_pagelist()")
Cc: stable <redacted>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20210927113702.3866843-1-arnd@kernel.org (local)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
index b25369a13452..967f10b9582a 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c

@@ -182,7 +182,7 @@ create_pagelist(char *buf, char __user *ubuf,
 		offset = (uintptr_t)ubuf & (PAGE_SIZE - 1);
 	num_pages = DIV_ROUND_UP(count + offset, PAGE_SIZE);
 
-	if (num_pages > (SIZE_MAX - sizeof(struct pagelist) -
+	if ((size_t)num_pages > (SIZE_MAX - sizeof(struct pagelist) -
 			 sizeof(struct vchiq_pagelist_info)) /
 			(sizeof(u32) + sizeof(pages[0]) +
 			 sizeof(struct scatterlist)))