[PATCH 3/5] scsi: mpt3sas: Avoid possible run-time warning with long manufacturer strings

[Kees Cook <keescook@chromium.org>]

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.

Fixes: b7e9712a02e8 ("scsi: mpt3sas: Replace deprecated strncpy() with strscpy()")
Signed-off-by: Kees Cook <keescook@chromium.org>
---
Cc: Justin Stitt <justinstitt@google.com>
Cc: Sathya Prakash <sathya.prakash@broadcom.com>
Cc: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Cc: Suganath Prabu Subramani <suganath-prabu.subramani@broadcom.com>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: MPT-FusionLinux.pdl@broadcom.com
Cc: linux-scsi@vger.kernel.org
---
 drivers/scsi/mpt3sas/mpt3sas_base.c      |  2 +-
 drivers/scsi/mpt3sas/mpt3sas_transport.c | 14 +++++---------
 2 files changed, 6 insertions(+), 10 deletions(-)

diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c
index 258647fc6bdd..1320e06727df 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
@@ -4774,7 +4774,7 @@ _base_display_ioc_capabilities(struct MPT3SAS_ADAPTER *ioc)
 	char desc[17] = {0};
 	u32 iounit_pg1_flags;
 
-	strscpy(desc, ioc->manu_pg0.ChipName, sizeof(desc));
+	memtostr(desc, ioc->manu_pg0.ChipName);
 	ioc_info(ioc, "%s: FWVersion(%02d.%02d.%02d.%02d), ChipRevision(0x%02x)\n",
 		 desc,
 		 (ioc->facts.FWVersion.Word & 0xFF000000) >> 24,
diff --git a/drivers/scsi/mpt3sas/mpt3sas_transport.c b/drivers/scsi/mpt3sas/mpt3sas_transport.c
index 76f9a9177198..d84413b77d84 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_transport.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_transport.c
@@ -458,17 +458,13 @@ _transport_expander_report_manufacture(struct MPT3SAS_ADAPTER *ioc,
 			goto out;
 
 		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 & 1;
 		if (edev->level) {
-			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