| Message ID | 20250227173936.7746-2-thorsten.blum@linux.dev (mailing list archive) |
|---|---|
| State | In Next |
| Commit | 69af654bf97232cf13a3924c27eac559b6fac951 |
| Headers | show |
| Series | hwmon: (pmbus/core) Replace deprecated strncpy() with strscpy() | expand |
On 2/27/25 09:39, Thorsten Blum wrote: > strncpy() is deprecated for NUL-terminated destination buffers; use > strscpy() instead. > > Compile-tested only. > > Link: https://github.com/KSPP/linux/issues/90 > Cc: linux-hardening@vger.kernel.org > Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> > --- > drivers/hwmon/pmbus/pmbus_core.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c > index 787683e83db6..cdde8b03a6e9 100644 > --- a/drivers/hwmon/pmbus/pmbus_core.c > +++ b/drivers/hwmon/pmbus/pmbus_core.c > @@ -1470,8 +1470,7 @@ static int pmbus_add_label(struct pmbus_data *data, > snprintf(label->name, sizeof(label->name), "%s%d_label", name, seq); > if (!index) { > if (phase == 0xff) > - strncpy(label->label, lstring, > - sizeof(label->label) - 1); > + strscpy(label->label, lstring); What guarantees that strlen(lstring) < sizeof(label->label) ? Guenter > else > snprintf(label->label, sizeof(label->label), "%s.%d", > lstring, phase);
On 27. Feb 2025, at 23:37, Guenter Roeck wrote: > On 2/27/25 09:39, Thorsten Blum wrote: >> strncpy() is deprecated for NUL-terminated destination buffers; use >> strscpy() instead. >> Compile-tested only. >> Link: https://github.com/KSPP/linux/issues/90 >> Cc: linux-hardening@vger.kernel.org >> Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> >> --- > > What guarantees that strlen(lstring) < sizeof(label->label) ? Hi Guenter, I don't think it matters for this patch. If lstring >= label, strscpy() behaves the same as strncpy() because the size argument is now one byte larger. If lstring < label, strscpy() NUL-terminates the destination buffer, but doesn't add NUL-padding compared to strncpy(). However, this doesn't matter because label is already zero-initialized. Thanks, Thorsten
On Thu, Feb 27, 2025 at 06:39:33PM +0100, Thorsten Blum wrote: > strncpy() is deprecated for NUL-terminated destination buffers; use > strscpy() instead. > > Compile-tested only. > > Link: https://github.com/KSPP/linux/issues/90 > Cc: linux-hardening@vger.kernel.org > Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> Applied. > --- > drivers/hwmon/pmbus/pmbus_core.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c > index 787683e83db6..cdde8b03a6e9 100644 > --- a/drivers/hwmon/pmbus/pmbus_core.c > +++ b/drivers/hwmon/pmbus/pmbus_core.c > @@ -1470,8 +1470,7 @@ static int pmbus_add_label(struct pmbus_data *data, > snprintf(label->name, sizeof(label->name), "%s%d_label", name, seq); > if (!index) { > if (phase == 0xff) > - strncpy(label->label, lstring, > - sizeof(label->label) - 1); > + strscpy(label->label, lstring); I added a note explaining that strscpy() uses sizeof(label->label) if the length of the destination buffer is not provided. Guenter
diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c index 787683e83db6..cdde8b03a6e9 100644 --- a/drivers/hwmon/pmbus/pmbus_core.c +++ b/drivers/hwmon/pmbus/pmbus_core.c @@ -1470,8 +1470,7 @@ static int pmbus_add_label(struct pmbus_data *data, snprintf(label->name, sizeof(label->name), "%s%d_label", name, seq); if (!index) { if (phase == 0xff) - strncpy(label->label, lstring, - sizeof(label->label) - 1); + strscpy(label->label, lstring); else snprintf(label->label, sizeof(label->label), "%s.%d", lstring, phase);
strncpy() is deprecated for NUL-terminated destination buffers; use strscpy() instead. Compile-tested only. Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@vger.kernel.org Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> --- drivers/hwmon/pmbus/pmbus_core.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)