[PATCH 5.4 13/24] ACPI: resource: Fix memory resource type union access

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

5.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

[ Upstream commit 7899ca9f3bd2b008e9a7c41f2a9f1986052d7e96 ]

In acpi_decode_space() addr->info.mem.caching is checked on main level
for any resource type but addr->info.mem is part of union and thus
valid only if the resource type is memory range.

Move the check inside the preceeding switch/case to only execute it
when the union is of correct type.

Fixes: fcb29bbcd540 ("ACPI: Add prefetch decoding to the address space parser")
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/20241202100614.20731-1-ilpo.jarvinen@linux.intel.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/acpi/resource.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
index 5e59344270ba..65567f26d7bd 100644
--- a/drivers/acpi/resource.c
+++ b/drivers/acpi/resource.c
@@ -250,6 +250,9 @@ static bool acpi_decode_space(struct resource_win *win,
 	switch (addr->resource_type) {
 	case ACPI_MEMORY_RANGE:
 		acpi_dev_memresource_flags(res, len, wp);
+
+		if (addr->info.mem.caching == ACPI_PREFETCHABLE_MEMORY)
+			res->flags |= IORESOURCE_PREFETCH;
 		break;
 	case ACPI_IO_RANGE:
 		acpi_dev_ioresource_flags(res, len, iodec,
@@ -265,9 +268,6 @@ static bool acpi_decode_space(struct resource_win *win,
 	if (addr->producer_consumer == ACPI_PRODUCER)
 		res->flags |= IORESOURCE_WINDOW;
 
-	if (addr->info.mem.caching == ACPI_PREFETCHABLE_MEMORY)
-		res->flags |= IORESOURCE_PREFETCH;
-
 	return !(res->flags & IORESOURCE_DISABLED);
 }
 
-- 
2.39.5