@p1 is assigned to @setup_buffer and then we manually assign a NUL-byte
at the first index. This renders the following strlen() call useless.
Moreover, we don't need to reassign p1 to setup_buffer for any reason --
neither do we need to manually set a NUL-byte at the end. strscpy()
resolves all this code making it easier to read.

Even considering the path where @str is falsey, the manual NUL-byte
assignment is useless as setup_buffer is declared with static storage
duration in the top-level scope which should NUL-initialize the whole
buffer.

Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Justin Stitt <justinstitt@google.com>
---
 drivers/scsi/wd33c93.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/scsi/wd33c93.c b/drivers/scsi/wd33c93.c
index e4fafc77bd20..a44b60c9004a 100644
--- a/drivers/scsi/wd33c93.c
+++ b/drivers/scsi/wd33c93.c
@@ -1721,9 +1721,7 @@ wd33c93_setup(char *str)
 	p1 = setup_buffer;
 	*p1 = '\0';
 	if (str)
-		strncpy(p1, str, SETUP_BUFFER_SIZE - strlen(setup_buffer));
-	setup_buffer[SETUP_BUFFER_SIZE - 1] = '\0';
-	p1 = setup_buffer;
+		strscpy(p1, str, SETUP_BUFFER_SIZE);
 	i = 0;
 	while (*p1 && (i < MAX_SETUP_ARGS)) {
 		p2 = strchr(p1, ',');

-- 
2.44.0.278.ge034bb2e1d-goog