[PATCH] acpi: fix check of length overflow

[Colin King]

From: Colin Ian King <colin.king at canonical.com>

The check for the accumulated string length is off-by-one as one needs to
include the end of string marker '\0', so use >= rather than >.  Also use
the sizeof() operator on must_be_id rather than a hard-coded length.

Fixes: ffea02df09d3 ("acpi: add fwts_acpi_space_id_check to check GAS adrress space ids")
Signed-off-by: Colin Ian King <colin.king at canonical.com>
---
 src/lib/src/fwts_acpi_tables.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/lib/src/fwts_acpi_tables.c b/src/lib/src/fwts_acpi_tables.c
index d832a65c..f2824cdf 100644
--- a/src/lib/src/fwts_acpi_tables.c
+++ b/src/lib/src/fwts_acpi_tables.c
@@ -1681,7 +1681,7 @@ void fwts_acpi_space_id_check(
 			continue;
 
 		length += strlen(id_name);
-		if (length > 255)
+		if (length >= sizeof(must_be_id))
 			continue;
 
 		strncat(must_be_id, id_name, strlen(id_name));
-- 
2.29.2