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: [email protected]
Signed-off-by: Justin Stitt <[email protected]>
---
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 <[email protected]>
On 10/24/23 12:52, Justin Stitt wrote:
> 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:
Please consider to remove the code for copying the sysfs string and to
use sysfs_match_string() instead.
Thanks,
Bart.
Hi,
On Tue, Oct 24, 2023 at 1:01 PM Bart Van Assche <[email protected]> wrote:
>
> On 10/24/23 12:52, Justin Stitt wrote:
> > 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:
>
> Please consider to remove the code for copying the sysfs string and to
> use sysfs_match_string() instead.
>
Sorry, I'm not too familiar with sysfs strings here.
Let me know what you think of this patch [1].
> Thanks,
>
> Bart.
>
[1]: https://lore.kernel.org/r/20231211-strncpy-drivers-scsi-fcoe-fcoe_sysfs-c-v1-1-73b942238396@google.com
Thanks
Justin
On 12/11/23 12:08, Justin Stitt wrote:
> Hi,
>
> On Tue, Oct 24, 2023 at 1:01 PM Bart Van Assche <[email protected]> wrote:
>>
>> On 10/24/23 12:52, Justin Stitt wrote:
>>> 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:
>>
>> Please consider to remove the code for copying the sysfs string and to
>> use sysfs_match_string() instead.
>>
>
> Sorry, I'm not too familiar with sysfs strings here.
>
> Let me know what you think of this patch [1].
I don't use FCoE so I will leave it to an FCoE user to review that patch.
Thanks,
Bart.