[PATCH 2/5] scsi: mptfusion: Avoid possible run-time warning with long manufacturer strings

[Kees Cook]

The prior strscpy() replacement of strncpy() here expected the
manufacture_reply strings to be NUL-terminated, but it is possible
they are not, as the code pattern here shows, e.g., edev->vendor_id
being exactly 1 character larger than manufacture_reply->vendor_id,
and the replaced strncpy() was copying only up to the size of the
source character array. Replace this with memtostr(), which is the
unambiguous way to convert a maybe not-NUL-terminated character array
into a NUL-terminated string.

Reported-by: Charles Bertsch <cbertsch@xxxxxxx>
Closes: https://lore.kernel.org/all/5445ba0f-3e27-4d43-a9ba-0cc22ada2fce@xxxxxxx/
Fixes: 45e833f0e5bb ("scsi: message: fusion: Replace deprecated strncpy() with strscpy()")
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
Cc: Justin Stitt <justinstitt@xxxxxxxxxx>
Cc: Sathya Prakash <sathya.prakash@xxxxxxxxxxxx>
Cc: Sreekanth Reddy <sreekanth.reddy@xxxxxxxxxxxx>
Cc: Suganath Prabu Subramani <suganath-prabu.subramani@xxxxxxxxxxxx>
Cc: MPT-FusionLinux.pdl@xxxxxxxxxxxx
Cc: linux-scsi@xxxxxxxxxxxxxxx
---
 drivers/message/fusion/mptsas.c | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/drivers/message/fusion/mptsas.c b/drivers/message/fusion/mptsas.c
index 300f8e955a53..0f80c840afc3 100644
--- a/drivers/message/fusion/mptsas.c
+++ b/drivers/message/fusion/mptsas.c
@@ -2964,17 +2964,13 @@ mptsas_exp_repmanufacture_info(MPT_ADAPTER *ioc,
 			goto out_free;
 
 		manufacture_reply = data_out + sizeof(struct rep_manu_request);
-		strscpy(edev->vendor_id, manufacture_reply->vendor_id,
-			sizeof(edev->vendor_id));
-		strscpy(edev->product_id, manufacture_reply->product_id,
-			sizeof(edev->product_id));
-		strscpy(edev->product_rev, manufacture_reply->product_rev,
-			sizeof(edev->product_rev));
+		memtostr(edev->vendor_id, manufacture_reply->vendor_id);
+		memtostr(edev->product_id, manufacture_reply->product_id);
+		memtostr(edev->product_rev, manufacture_reply->product_rev);
 		edev->level = manufacture_reply->sas_format;
 		if (manufacture_reply->sas_format) {
-			strscpy(edev->component_vendor_id,
-				manufacture_reply->component_vendor_id,
-				sizeof(edev->component_vendor_id));
+			memtostr(edev->component_vendor_id,
+				 manufacture_reply->component_vendor_id);
 			tmp = (u8 *)&manufacture_reply->component_id;
 			edev->component_id = tmp[0] << 8 | tmp[1];
 			edev->component_revision_id =
-- 
2.34.1