scsi: ibmvscsi: Replace deprecated strncpy() with strscpy()

strncpy() is deprecated for use on NUL-terminated destination strings [1]
and as such we should prefer more robust and less ambiguous string
interfaces.

We expect partition_name to be NUL-terminated based on its usage with
format strings:
|       dev_info(hostdata->dev, "host srp version: %s, "
|                "host partition %s (%d), OS %d, max io %u\n",
|                hostdata->madapter_info.srp_version,
|                hostdata->madapter_info.partition_name,
|                be32_to_cpu(hostdata->madapter_info.partition_number),
|                be32_to_cpu(hostdata->madapter_info.os_type),
|                be32_to_cpu(hostdata->madapter_info.port_max_txu[0]));
...
|       len = snprintf(buf, PAGE_SIZE, "%s\n",
|                hostdata->madapter_info.partition_name);

Moreover, NUL-padding is not required as madapter_info is explicitly
memset to 0:
|       memset(&hostdata->madapter_info, 0x00,
|                       sizeof(hostdata->madapter_info));

Considering the above, a suitable replacement is strscpy() [2] due to the
fact that it guarantees NUL-termination on the destination buffer without
unnecessarily NUL-padding.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html
Link: https://github.com/KSPP/linux/issues/90
Cc: <linux-hardening@vger.kernel.org>
Signed-off-by: Justin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/r/20231030-strncpy-drivers-scsi-ibmvscsi-ibmvscsi-c-v1-1-f8b06ae9e3d5@google.com
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c
index 59599299615d4ccf951d7fea93b91f169d70010c..71f3e9563520ba81c9e9a6de78e4b20dcd7edf21 100644 (file)
--- a/drivers/scsi/ibmvscsi/ibmvscsi.c
+++ b/drivers/scsi/ibmvscsi/ibmvscsi.c
@@ -266,7 +266,7 @@ static void set_adapter_info(struct ibmvscsi_host_data *hostdata)
        dev_info(hostdata->dev, "SRP_VERSION: %s\n", SRP_VERSION);
        strcpy(hostdata->madapter_info.srp_version, SRP_VERSION);
 
-       strncpy(hostdata->madapter_info.partition_name, partition_name,
+       strscpy(hostdata->madapter_info.partition_name, partition_name,
                        sizeof(hostdata->madapter_info.partition_name));
 
        hostdata->madapter_info.partition_number =