drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
strncpy() is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.
psvt->limit.string can only be 8 bytes so let's use the appropriate size
macro ACPI_LIMIT_STR_MAX_LEN.
Neither psvt->limit.string or psvt_user[i].limit.string requires the
NUL-padding behavior that strncpy() provides as they have both been
filled with NUL-bytes prior to the string operation.
| memset(&psvt->limit, 0, sizeof(u64));
and
| psvt_user = kzalloc(psvt_len, GFP_KERNEL);
Let's use `strscpy` [2] due to the fact that it guarantees
NUL-termination on the destination buffer without unnecessarily
NUL-padding.
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@vger.kernel.org
Signed-off-by: Justin Stitt <justinstitt@google.com>
---
Note: build-tested only.
Found with: $ rg "strncpy\("
---
drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.c b/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.c
index dc519a665c18..4b4a4d63e61f 100644
--- a/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.c
+++ b/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.c
@@ -309,7 +309,7 @@ static int acpi_parse_psvt(acpi_handle handle, int *psvt_count, struct psvt **ps
if (knob->type == ACPI_TYPE_STRING) {
memset(&psvt->limit, 0, sizeof(u64));
- strncpy(psvt->limit.string, psvt_ptr->limit.str_ptr, knob->string.length);
+ strscpy(psvt->limit.string, psvt_ptr->limit.str_ptr, ACPI_LIMIT_STR_MAX_LEN);
} else {
psvt->limit.integer = psvt_ptr->limit.integer;
}
@@ -468,7 +468,7 @@ static int fill_psvt(char __user *ubuf)
psvt_user[i].unlimit_coeff = psvts[i].unlimit_coeff;
psvt_user[i].control_knob_type = psvts[i].control_knob_type;
if (psvt_user[i].control_knob_type == ACPI_TYPE_STRING)
- strncpy(psvt_user[i].limit.string, psvts[i].limit.string,
+ strscpy(psvt_user[i].limit.string, psvts[i].limit.string,
ACPI_LIMIT_STR_MAX_LEN);
else
psvt_user[i].limit.integer = psvts[i].limit.integer;
---
base-commit: bf3a69c6861ff4dc7892d895c87074af7bc1c400
change-id: 20240318-strncpy-drivers-thermal-intel-int340x_thermal-acpi_thermal_rel-c-17070c1e42f3
Best regards,
--
Justin Stitt <justinstitt@google.com>On Mon, Mar 18, 2024 at 11:36 PM Justin Stitt <justinstitt@google.com> wrote:
>
> strncpy() is deprecated for use on NUL-terminated destination strings
> [1] and as such we should prefer more robust and less ambiguous string
> interfaces.
>
> psvt->limit.string can only be 8 bytes so let's use the appropriate size
> macro ACPI_LIMIT_STR_MAX_LEN.
>
> Neither psvt->limit.string or psvt_user[i].limit.string requires the
> NUL-padding behavior that strncpy() provides as they have both been
> filled with NUL-bytes prior to the string operation.
> | memset(&psvt->limit, 0, sizeof(u64));
> and
> | psvt_user = kzalloc(psvt_len, GFP_KERNEL);
>
> Let's use `strscpy` [2] due to the fact that it guarantees
> NUL-termination on the destination buffer without unnecessarily
> NUL-padding.
>
> 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@vger.kernel.org
> Signed-off-by: Justin Stitt <justinstitt@google.com>
Srinivas, any objections?
> ---
> Note: build-tested only.
>
> Found with: $ rg "strncpy\("
> ---
> drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.c b/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.c
> index dc519a665c18..4b4a4d63e61f 100644
> --- a/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.c
> +++ b/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.c
> @@ -309,7 +309,7 @@ static int acpi_parse_psvt(acpi_handle handle, int *psvt_count, struct psvt **ps
>
> if (knob->type == ACPI_TYPE_STRING) {
> memset(&psvt->limit, 0, sizeof(u64));
> - strncpy(psvt->limit.string, psvt_ptr->limit.str_ptr, knob->string.length);
> + strscpy(psvt->limit.string, psvt_ptr->limit.str_ptr, ACPI_LIMIT_STR_MAX_LEN);
> } else {
> psvt->limit.integer = psvt_ptr->limit.integer;
> }
> @@ -468,7 +468,7 @@ static int fill_psvt(char __user *ubuf)
> psvt_user[i].unlimit_coeff = psvts[i].unlimit_coeff;
> psvt_user[i].control_knob_type = psvts[i].control_knob_type;
> if (psvt_user[i].control_knob_type == ACPI_TYPE_STRING)
> - strncpy(psvt_user[i].limit.string, psvts[i].limit.string,
> + strscpy(psvt_user[i].limit.string, psvts[i].limit.string,
> ACPI_LIMIT_STR_MAX_LEN);
> else
> psvt_user[i].limit.integer = psvts[i].limit.integer;
>
> ---
> base-commit: bf3a69c6861ff4dc7892d895c87074af7bc1c400
> change-id: 20240318-strncpy-drivers-thermal-intel-int340x_thermal-acpi_thermal_rel-c-17070c1e42f3
>
> Best regards,
> --
> Justin Stitt <justinstitt@google.com>
>
On Tue, 2024-03-19 at 12:39 +0100, Rafael J. Wysocki wrote:
> On Mon, Mar 18, 2024 at 11:36 PM Justin Stitt
> <justinstitt@google.com> wrote:
> >
> > strncpy() is deprecated for use on NUL-terminated destination
> > strings
> > [1] and as such we should prefer more robust and less ambiguous
> > string
> > interfaces.
> >
> > psvt->limit.string can only be 8 bytes so let's use the appropriate
> > size
> > macro ACPI_LIMIT_STR_MAX_LEN.
> >
> > Neither psvt->limit.string or psvt_user[i].limit.string requires
> > the
> > NUL-padding behavior that strncpy() provides as they have both been
> > filled with NUL-bytes prior to the string operation.
> > > memset(&psvt->limit, 0, sizeof(u64));
> > and
> > > psvt_user = kzalloc(psvt_len, GFP_KERNEL);
> >
> > Let's use `strscpy` [2] due to the fact that it guarantees
> > NUL-termination on the destination buffer without unnecessarily
> > NUL-padding.
> >
> > 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@vger.kernel.org
> > Signed-off-by: Justin Stitt <justinstitt@google.com>
>
> Srinivas, any objections?
No
Reviewed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
>
> > ---
> > Note: build-tested only.
> >
> > Found with: $ rg "strncpy\("
> > ---
> > drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git
> > a/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.c
> > b/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.c
> > index dc519a665c18..4b4a4d63e61f 100644
> > --- a/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.c
> > +++ b/drivers/thermal/intel/int340x_thermal/acpi_thermal_rel.c
> > @@ -309,7 +309,7 @@ static int acpi_parse_psvt(acpi_handle handle,
> > int *psvt_count, struct psvt **ps
> >
> > if (knob->type == ACPI_TYPE_STRING) {
> > memset(&psvt->limit, 0, sizeof(u64));
> > - strncpy(psvt->limit.string, psvt_ptr-
> > >limit.str_ptr, knob->string.length);
> > + strscpy(psvt->limit.string, psvt_ptr-
> > >limit.str_ptr, ACPI_LIMIT_STR_MAX_LEN);
> > } else {
> > psvt->limit.integer = psvt_ptr-
> > >limit.integer;
> > }
> > @@ -468,7 +468,7 @@ static int fill_psvt(char __user *ubuf)
> > psvt_user[i].unlimit_coeff =
> > psvts[i].unlimit_coeff;
> > psvt_user[i].control_knob_type =
> > psvts[i].control_knob_type;
> > if (psvt_user[i].control_knob_type ==
> > ACPI_TYPE_STRING)
> > - strncpy(psvt_user[i].limit.string,
> > psvts[i].limit.string,
> > + strscpy(psvt_user[i].limit.string,
> > psvts[i].limit.string,
> > ACPI_LIMIT_STR_MAX_LEN);
> > else
> > psvt_user[i].limit.integer =
> > psvts[i].limit.integer;
> >
> > ---
> > base-commit: bf3a69c6861ff4dc7892d895c87074af7bc1c400
> > change-id: 20240318-strncpy-drivers-thermal-intel-int340x_thermal-
> > acpi_thermal_rel-c-17070c1e42f3
> >
> > Best regards,
> > --
> > Justin Stitt <justinstitt@google.com>
> >
On Tue, Mar 19, 2024 at 5:20 PM srinivas pandruvada <srinivas.pandruvada@linux.intel.com> wrote: > > On Tue, 2024-03-19 at 12:39 +0100, Rafael J. Wysocki wrote: > > On Mon, Mar 18, 2024 at 11:36 PM Justin Stitt > > <justinstitt@google.com> wrote: > > > > > > strncpy() is deprecated for use on NUL-terminated destination > > > strings > > > [1] and as such we should prefer more robust and less ambiguous > > > string > > > interfaces. > > > > > > psvt->limit.string can only be 8 bytes so let's use the appropriate > > > size > > > macro ACPI_LIMIT_STR_MAX_LEN. > > > > > > Neither psvt->limit.string or psvt_user[i].limit.string requires > > > the > > > NUL-padding behavior that strncpy() provides as they have both been > > > filled with NUL-bytes prior to the string operation. > > > > memset(&psvt->limit, 0, sizeof(u64)); > > > and > > > > psvt_user = kzalloc(psvt_len, GFP_KERNEL); > > > > > > Let's use `strscpy` [2] due to the fact that it guarantees > > > NUL-termination on the destination buffer without unnecessarily > > > NUL-padding. > > > > > > 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@vger.kernel.org > > > Signed-off-by: Justin Stitt <justinstitt@google.com> > > > > Srinivas, any objections? > No > > Reviewed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Applied as 6.10 material, thanks!
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