[libcamera-devel] [PATCH 6/7] libcamera: yaml_parser: Fix range checks for 32-bit integers

[Hanlin Chen]

Hi Laurent

On Thu, Jun 16, 2022 at 05:24:02PM +0300, Laurent Pinchart via
libcamera-devel wrote:
> The strtol() and strtoul() functions return long integers, which may be
> larger than 32-bit integers. Add manual range checks.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

Reviewed-by: Han-Lin Chen <hanlinchen at chromium.org>

Thanks for the fix!

On Thu, Jun 16, 2022 at 10:24 PM Laurent Pinchart via libcamera-devel
<libcamera-devel at lists.libcamera.org> wrote:
>
> The strtol() and strtoul() functions return long integers, which may be
> larger than 32-bit integers. Add manual range checks.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> ---
>  src/libcamera/yaml_parser.cpp | 13 +++++++++----
>  1 file changed, 9 insertions(+), 4 deletions(-)
>
> diff --git a/src/libcamera/yaml_parser.cpp b/src/libcamera/yaml_parser.cpp
> index 9b6e70cbfcf3..bd4b501b1422 100644
> --- a/src/libcamera/yaml_parser.cpp
> +++ b/src/libcamera/yaml_parser.cpp
> @@ -10,6 +10,7 @@
>  #include <cstdlib>
>  #include <errno.h>
>  #include <functional>
> +#include <limits>
>
>  #include <libcamera/base/file.h>
>  #include <libcamera/base/log.h>
> @@ -151,9 +152,11 @@ int32_t YamlObject::get(const int32_t &defaultValue, bool *ok) const
>         char *end;
>
>         errno = 0;
> -       int32_t value = std::strtol(value_.c_str(), &end, 10);
> +       long value = std::strtol(value_.c_str(), &end, 10);
>
> -       if ('\0' != *end || errno == ERANGE)
> +       if ('\0' != *end || errno == ERANGE ||
> +           value < std::numeric_limits<int32_t>::min() ||
> +           value > std::numeric_limits<int32_t>::max())
>                 return defaultValue;
>
>         setOk(ok, true);
> @@ -185,9 +188,11 @@ uint32_t YamlObject::get(const uint32_t &defaultValue, bool *ok) const
>         char *end;
>
>         errno = 0;
> -       uint32_t value = std::strtoul(value_.c_str(), &end, 10);
> +       unsigned long value = std::strtoul(value_.c_str(), &end, 10);
>
> -       if ('\0' != *end || errno == ERANGE)
> +       if ('\0' != *end || errno == ERANGE ||
> +           value < std::numeric_limits<uint32_t>::min() ||
> +           value > std::numeric_limits<uint32_t>::max())
>                 return defaultValue;
>
>         setOk(ok, true);
> --
> Regards,
>
> Laurent Pinchart
>