[PATCH 4.15 065/105] ACPI / watchdog: Fix off-by-one error at resource assignment

From: Greg Kroah-Hartman
Date: Tue Mar 27 2018 - 12:41:27 EST


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

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

From: Takashi Iwai <tiwai@xxxxxxx>

commit b1abf6fc49829d89660c961fafe3f90f3d843c55 upstream.

The resource allocation in WDAT watchdog has off-one-by error, it sets
one byte more than the actual end address. This may eventually lead
to unexpected resource conflicts.

Fixes: 058dfc767008 (ACPI / watchdog: Add support for WDAT hardware watchdog)
Cc: 4.9+ <stable@xxxxxxxxxxxxxxx> # 4.9+
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Acked-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
Acked-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/acpi/acpi_watchdog.c | 4 ++--
drivers/watchdog/wdat_wdt.c | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/acpi/acpi_watchdog.c
+++ b/drivers/acpi/acpi_watchdog.c
@@ -74,10 +74,10 @@ void __init acpi_watchdog_init(void)
res.start = gas->address;
if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
res.flags = IORESOURCE_MEM;
- res.end = res.start + ALIGN(gas->access_width, 4);
+ res.end = res.start + ALIGN(gas->access_width, 4) - 1;
} else if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
res.flags = IORESOURCE_IO;
- res.end = res.start + gas->access_width;
+ res.end = res.start + gas->access_width - 1;
} else {
pr_warn("Unsupported address space: %u\n",
gas->space_id);
--- a/drivers/watchdog/wdat_wdt.c
+++ b/drivers/watchdog/wdat_wdt.c
@@ -392,7 +392,7 @@ static int wdat_wdt_probe(struct platfor

memset(&r, 0, sizeof(r));
r.start = gas->address;
- r.end = r.start + gas->access_width;
+ r.end = r.start + gas->access_width - 1;
if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
r.flags = IORESOURCE_MEM;
} else if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {