From 4a798f508f5d0809f45c939e329e17b3eb0ffbc1 Mon Sep 17 00:00:00 2001 From: Colin Ian King Date: Fri, 18 Mar 2016 15:08:01 +0000 Subject: [PATCH] ACPI / util: cast data to u64 before shifting to fix sign extension obj->buffer.pointer[i] should be cast to u64 to prevent an unintentional sign extension. For example, if pointer[7] is 0x80, then the value 0xffffffffff000000 is or'd into mask rather than the intended value 0xff00000000000000 Detected with static analysis by CoverityScan Signed-off-by: Colin Ian King Signed-off-by: Rafael J. Wysocki --- drivers/acpi/utils.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c index f12a72428aac..050673f0c0b3 100644 --- a/drivers/acpi/utils.c +++ b/drivers/acpi/utils.c @@ -692,7 +692,7 @@ bool acpi_check_dsm(acpi_handle handle, const u8 *uuid, int rev, u64 funcs) mask = obj->integer.value; else if (obj->type == ACPI_TYPE_BUFFER) for (i = 0; i < obj->buffer.length && i < 8; i++) - mask |= (((u8)obj->buffer.pointer[i]) << (i * 8)); + mask |= (((u64)obj->buffer.pointer[i]) << (i * 8)); ACPI_FREE(obj); /* -- 2.20.1