[PATCH ethtool 5/8] module-common: Avoid undefined behavior with CMIS transceivers

[Ido Schimmel <idosch@nvidia.com>]

While the function that handles the printing of the transmitter
technology handles all the values passed by the SFF-8636 parser (0-15),
it does not handle all the values that can be passed by the CMIS parser
where this field is 8-bits.

Fix by adding a default case that will initialize "description" to
"Reserved or unknown".

Fixes: 88ca347ef35a ("Add QSFP-DD support")
Reviewed-by: Danielle Ratson <danieller@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
---
 module-common.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/module-common.c b/module-common.c
index 997dd2b37ce7..ea4514ab3899 100644
--- a/module-common.c
+++ b/module-common.c
@@ -628,6 +628,9 @@ void module_show_mit_compliance(u16 value)
 		snprintf(description, SFF_MAX_DESC_LEN, "%s linear active equalizers",
 			 cc);
 		break;
+	default:
+		strncpy(description, "Reserved or unknown", SFF_MAX_DESC_LEN);
+		break;
 	}
 
 	sff_print_any_hex_field("Transmitter technology",
-- 
2.55.0