[PATCH 4.14 26/55] scsi: scsi_devinfo: cleanly zero-pad devinfo strings

Greg Kroah-Hartman
2018-12-06T14:43:58Z

From: Martin Wilck <mwilck@suse.com>

commit 81df022b688d43d2a3667518b2f755d384397910 upstream.

Cleanly fill memory for "vendor" and "model" with 0-bytes for the
"compatible" case rather than adding only a single 0 byte. This
simplifies the devinfo code a a bit, and avoids mistakes in other places
of the code (not in current upstream, but we had one such mistake in the
SUSE kernel).

[mkp: applied by hand and added braces]

Signed-off-by: Martin Wilck <mwilck@suse.com>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/scsi/scsi_devinfo.c | 22 +++++++---------------
1 file changed, 7 insertions(+), 15 deletions(-)

--- a/drivers/scsi/scsi_devinfo.c
+++ b/drivers/scsi/scsi_devinfo.c
@@ -34,7 +34,6 @@ struct scsi_dev_info_list_table {
};

-static const char spaces[] = " "; /* 16 of them */
static unsigned scsi_default_dev_flags;
static LIST_HEAD(scsi_dev_info_list);
static char scsi_dev_flags[256];
@@ -296,20 +295,13 @@ static void scsi_strcpy_devinfo(char *na
size_t from_length;

from_length = strlen(from);
- strncpy(to, from, min(to_length, from_length));
- if (from_length < to_length) {
- if (compatible) {
- /*
- * NUL terminate the string if it is short.
- */
- to[from_length] = '\0';
- } else {
- /*
- * space pad the string if it is short.
- */
- strncpy(&to[from_length], spaces,
- to_length - from_length);
- }
+ /* this zero-pads the destination */
+ strncpy(to, from, to_length);
+ if (from_length < to_length && !compatible) {
+ /*
+ * space pad the string if it is short.
+ */
+ memset(&to[from_length], ' ', to_length - from_length);
}
if (from_length > to_length)
printk(KERN_WARNING "%s: %s string '%s' is too long\n",