| Message ID | 20230919-strncpy-drivers-hwmon-acpi_power_meter-c-v2-1-8348432d6442@google.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2] hwmon: refactor deprecated strncpy | expand |
On 2023-09-19 05:07:55+0000, Justin Stitt wrote: > `strncpy` is deprecated for use on NUL-terminated destination strings [1]. > > A trailing zero is already handled by the kcalloc > | *str = kcalloc(element->string.length + 1, sizeof(u8), GFP_KERNEL); > ... which makes memcpy() a suitable replacement to strncpy. > > Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] > Link: https://github.com/KSPP/linux/issues/90 > Cc: linux-hardening@vger.kernel.org > Signed-off-by: Justin Stitt <justinstitt@google.com> > --- > Changes in v2: > - use memcpy over strscpy (thanks Kees) > - Link to v1: https://lore.kernel.org/r/20230914-strncpy-drivers-hwmon-acpi_power_meter-c-v1-1-905297479fe8@google.com > --- > drivers/hwmon/acpi_power_meter.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/hwmon/acpi_power_meter.c b/drivers/hwmon/acpi_power_meter.c > index fa28d447f0df..82e99aec4a33 100644 > --- a/drivers/hwmon/acpi_power_meter.c > +++ b/drivers/hwmon/acpi_power_meter.c > @@ -803,7 +803,7 @@ static int read_capabilities(struct acpi_power_meter_resource *resource) > goto error; > } > > - strncpy(*str, element->string.pointer, element->string.length); > + memcpy(*str, element->string.pointer, element->string.length); Isn't this now essentially the same as kmemdup_nul()? > str++; > } > > > --- > base-commit: 3669558bdf354cd352be955ef2764cde6a9bf5ec > change-id: 20230914-strncpy-drivers-hwmon-acpi_power_meter-c-c9f2d8053bef > > Best regards, > -- > Justin Stitt <justinstitt@google.com> >
On Tue, Sep 19, 2023 at 09:02:49AM +0200, Thomas Weißschuh wrote: > On 2023-09-19 05:07:55+0000, Justin Stitt wrote: > > `strncpy` is deprecated for use on NUL-terminated destination strings [1]. > > > > A trailing zero is already handled by the kcalloc > > | *str = kcalloc(element->string.length + 1, sizeof(u8), GFP_KERNEL); > > ... which makes memcpy() a suitable replacement to strncpy. > > > > Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] > > Link: https://github.com/KSPP/linux/issues/90 > > Cc: linux-hardening@vger.kernel.org > > Signed-off-by: Justin Stitt <justinstitt@google.com> > > --- > > Changes in v2: > > - use memcpy over strscpy (thanks Kees) > > - Link to v1: https://lore.kernel.org/r/20230914-strncpy-drivers-hwmon-acpi_power_meter-c-v1-1-905297479fe8@google.com > > --- > > drivers/hwmon/acpi_power_meter.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/hwmon/acpi_power_meter.c b/drivers/hwmon/acpi_power_meter.c > > index fa28d447f0df..82e99aec4a33 100644 > > --- a/drivers/hwmon/acpi_power_meter.c > > +++ b/drivers/hwmon/acpi_power_meter.c > > @@ -803,7 +803,7 @@ static int read_capabilities(struct acpi_power_meter_resource *resource) > > goto error; > > } > > > > - strncpy(*str, element->string.pointer, element->string.length); > > + memcpy(*str, element->string.pointer, element->string.length); > > Isn't this now essentially the same as kmemdup_nul()? Ah, yeah, good catch. I should add a note that the reverse of strtomem() is kmemdup_nul() :) Justin, can you refactor this to use kmemdup_nul() instead? -Kees
diff --git a/drivers/hwmon/acpi_power_meter.c b/drivers/hwmon/acpi_power_meter.c index fa28d447f0df..82e99aec4a33 100644 --- a/drivers/hwmon/acpi_power_meter.c +++ b/drivers/hwmon/acpi_power_meter.c @@ -803,7 +803,7 @@ static int read_capabilities(struct acpi_power_meter_resource *resource) goto error; } - strncpy(*str, element->string.pointer, element->string.length); + memcpy(*str, element->string.pointer, element->string.length); str++; }
`strncpy` is deprecated for use on NUL-terminated destination strings [1]. A trailing zero is already handled by the kcalloc | *str = kcalloc(element->string.length + 1, sizeof(u8), GFP_KERNEL); ... which makes memcpy() a suitable replacement to strncpy. Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@vger.kernel.org Signed-off-by: Justin Stitt <justinstitt@google.com> --- Changes in v2: - use memcpy over strscpy (thanks Kees) - Link to v1: https://lore.kernel.org/r/20230914-strncpy-drivers-hwmon-acpi_power_meter-c-v1-1-905297479fe8@google.com --- drivers/hwmon/acpi_power_meter.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- base-commit: 3669558bdf354cd352be955ef2764cde6a9bf5ec change-id: 20230914-strncpy-drivers-hwmon-acpi_power_meter-c-c9f2d8053bef Best regards, -- Justin Stitt <justinstitt@google.com>