The patch below does not apply to the 4.9-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 stable@vger.kernel.org.

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 stable@vger.kernel.org Signed-off-by: Arnd Bergmann arnd@arndb.de Link: https://lore.kernel.org/r/20210927113702.3866843-1-arnd@kernel.org 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)))