Commit 15e2f65f authored by Thomas Weißschuh's avatar Thomas Weißschuh Committed by Rob Herring (Arm)
Browse files

of: address: Fix empty resource handling in __of_address_resource_bounds() 



"resource->end" needs to always be equal to "resource->start + size - 1".
The previous version of the function did not perform the "- 1" in case
of an empty resource.

Also make sure to allow an empty resource at address 0.

Reported-by: default avatarBasharath Hussain Khaja <basharath@couthit.com>
Closes: https://lore.kernel.org/lkml/20250108140414.13530-1-basharath@couthit.com/


Fixes: 1a52a094 ("of: address: Unify resource bounds overflow checking")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarThomas Weißschuh <thomas.weissschuh@linutronix.de>
Link: https://lore.kernel.org/r/20250120-of-address-overflow-v1-1-dd68dbf47bce@linutronix.de


Signed-off-by: default avatarRob Herring (Arm) <robh@kernel.org>
parent 14bce187

drivers/of/address.c

+5 −7
Original line number Diff line number Diff line
@@ -185,17 +185,15 @@ static u64 of_bus_pci_map(__be32 *addr, const __be32 *range, int na, int ns, 


static int __of_address_resource_bounds(struct resource *r, u64 start, u64 size)

{

	u64 end = start;



	if (overflows_type(start, r->start))

		return -EOVERFLOW;

	if (size && check_add_overflow(end, size - 1, &end))

		return -EOVERFLOW;

	if (overflows_type(end, r->end))

		return -EOVERFLOW;



	r->start = start;

	r->end = end;



	if (!size)

		r->end = wrapping_sub(typeof(r->end), r->start, 1);

	else if (size && check_add_overflow(r->start, size - 1, &r->end))

		return -EOVERFLOW;



	return 0;

}