[PATCH 4/5] scsi: mpi3mr: Avoid possible run-time warning with long manufacturer strings

Kees Cook
2024-04-10T02:32:00Z

The prior use of strscpy() 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 strscpy() 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: 2bd37e284914 ("scsi: mpi3mr: Add framework to issue MPT transport cmds")
Signed-off-by: Kees Cook <keescook@chromium.org>
---
Cc: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Cc: Sathya Prakash Veerichetty <sathya.prakash@broadcom.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Sumit Saxena <sumit.saxena@broadcom.com>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: mpi3mr-linuxdrv.pdl@broadcom.com
Cc: linux-scsi@vger.kernel.org
---
drivers/scsi/mpi3mr/mpi3mr_transport.c | 14 +++++---------
1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/drivers/scsi/mpi3mr/mpi3mr_transport.c b/drivers/scsi/mpi3mr/mpi3mr_transport.c
index dabb91f0f75d..3caceddb864a 100644
--- a/drivers/scsi/mpi3mr/mpi3mr_transport.c
+++ b/drivers/scsi/mpi3mr/mpi3mr_transport.c
@@ -211,17 +211,13 @@ static int mpi3mr_report_manufacture(struct mpi3mr_ioc *mrioc,
goto out;
}

- strscpy(edev->vendor_id, manufacture_reply->vendor_id,
- SAS_EXPANDER_VENDOR_ID_LEN);
- strscpy(edev->product_id, manufacture_reply->product_id,
- SAS_EXPANDER_PRODUCT_ID_LEN);
- strscpy(edev->product_rev, manufacture_reply->product_rev,
- SAS_EXPANDER_PRODUCT_REV_LEN);
+ 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,
- SAS_EXPANDER_COMPONENT_VENDOR_ID_LEN);
+ 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