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 `mode` to be NUL-terminated based on its usage with
strcasecmp():
| ctlr->mode = fcoe_parse_mode(mode);
...
| static enum fip_conn_type fcoe_parse_mode(const char *buf)
| {
| int i;
|
| for (i = 0; i < ARRAY_SIZE(fip_conn_type_names); i++) {
| if (strcasecmp(buf, fip_conn_type_names[i]) == 0)
| return i;
| }
|
| return FIP_CONN_TYPE_UNKNOWN;
| }
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.
We can drop the manual NUL-byte assignment but should keep the newline
removal so newlines don't creep into the string.
Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link: https://github.com/KSPP/linux/issues/90
Cc: linux-hardening@xxxxxxxxxxxxxxx
Signed-off-by: Justin Stitt <justinstitt@xxxxxxxxxx>
---
Note: build-tested only.
Found with: $ rg "strncpy\("
---
drivers/scsi/fcoe/fcoe_sysfs.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/drivers/scsi/fcoe/fcoe_sysfs.c b/drivers/scsi/fcoe/fcoe_sysfs.c
index e17957f8085c..7a3ca6cd3030 100644
--- a/drivers/scsi/fcoe/fcoe_sysfs.c
+++ b/drivers/scsi/fcoe/fcoe_sysfs.c
@@ -279,12 +279,10 @@ static ssize_t store_ctlr_mode(struct device *dev,
if (count > FCOE_MAX_MODENAME_LEN)
return -EINVAL;
- strncpy(mode, buf, count);
+ strscpy(mode, buf, count);
if (mode[count - 1] == '\n')
mode[count - 1] = '\0';
- else
- mode[count] = '\0';
switch (ctlr->enabled) {
case FCOE_CTLR_ENABLED:
---
base-commit: d88520ad73b79e71e3ddf08de335b8520ae41c5c
change-id: 20231024-strncpy-drivers-scsi-fcoe-fcoe_sysfs-c-0e1dffe82855
Best regards,
--
Justin Stitt <justinstitt@xxxxxxxxxx>
