scsi: wd33c93: Replace deprecated strncpy() with strscpy()

@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>
Link: https://lore.kernel.org/r/20240305-strncpy-drivers-scsi-mpi3mr-mpi3mr_fw-c-v3-7-5b78a13ff984@google.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/wd33c93.c b/drivers/scsi/wd33c93.c
index e4fafc77bd2010d6221e10932676312a1d1930a9..a44b60c9004ab0a5e01abbb05c4095e90ddaba2a 100644 (file)
--- 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, ',');