From: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Date: Thu, 5 Sep 2024 07:46:01 +0000 (+0200)
Subject: of: address: Report error on resource bounds overflow
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=000f6d588a8f3d128f89351058dc04d38e54a327;p=linux.git

of: address: Report error on resource bounds overflow

The members "start" and "end" of struct resource are of type
"resource_size_t" which can be 32bit wide.
Values read from OF however are always 64bit wide.
Avoid silently truncating the value and instead return an error value.

This can happen on real systems when the DT was created for a
PAE-enabled kernel and a non-PAE kernel is actually running.
For example with an arm defconfig and "qemu-system-arm -M virt".

Link: https://bugs.launchpad.net/qemu/+bug/1790975
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Tested-by: Nam Cao <namcao@linutronix.de>
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20240905-of-resource-overflow-v1-1-0cd8bb92cc1f@linutronix.de
Cc: stable@vger.kernel.org
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
---

diff --git a/drivers/of/address.c b/drivers/of/address.c
index d669ce25b5f9..7e59283a4472 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -8,6 +8,7 @@
 #include <linux/logic_pio.h>
 #include <linux/module.h>
 #include <linux/of_address.h>
+#include <linux/overflow.h>
 #include <linux/pci.h>
 #include <linux/pci_regs.h>
 #include <linux/sizes.h>
@@ -1061,7 +1062,11 @@ static int __of_address_to_resource(struct device_node *dev, int index, int bar_
 	if (of_mmio_is_nonposted(dev))
 		flags |= IORESOURCE_MEM_NONPOSTED;
 
+	if (overflows_type(taddr, r->start))
+		return -EOVERFLOW;
 	r->start = taddr;
+	if (overflows_type(taddr + size - 1, r->end))
+		return -EOVERFLOW;
 	r->end = taddr + size - 1;
 	r->flags = flags;
 	r->name = name ? name : dev->full_name;