Depending on the state of @compatible, we are going to do different
things with our @to buffer.
When @compatible is true we want a NUL-term'd and NUL-padded destination
buffer. Conversely, if @compatible is false we just want a space-padded
destination buffer (no NUL-term required).
As per:
/**
* scsi_dev_info_list_add_keyed - add one dev_info list entry.
* @compatible: if true, null terminate short strings. Otherwise space pad.
...
Note that we can't easily use `strtomem_pad` here as the size of the @to
buffer is unknown to the compiler due to indirection layers.
Now, the intent of the code is more clear (I probably didn't even need
to add a comment -- that's how clear it is).
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: Justin Stitt <justinstitt@xxxxxxxxxx>
---
drivers/scsi/scsi_devinfo.c | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)
diff --git a/drivers/scsi/scsi_devinfo.c b/drivers/scsi/scsi_devinfo.c
index 3fcaf10a9dfe..2d3dbce25629 100644
--- a/drivers/scsi/scsi_devinfo.c
+++ b/drivers/scsi/scsi_devinfo.c
@@ -293,14 +293,16 @@ static void scsi_strcpy_devinfo(char *name, char *to, size_t to_length,
size_t from_length;
from_length = strlen(from);
- /* 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);
- }
+
+ /*
+ * null pad and null terminate if compatible
+ * otherwise space pad
+ */
+ if (compatible)
+ strscpy_pad(to, from, to_length);
+ else
+ memcpy_and_pad(to, to_length, from, from_length, ' ');
+
if (from_length > to_length)
printk(KERN_WARNING "%s: %s string '%s' is too long\n",
__func__, name, from);
--
2.44.0.278.ge034bb2e1d-goog
