diff options
| author | Justin Stitt <justinstitt@google.com> | 2023-10-16 22:38:20 +0000 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2023-12-01 09:51:43 -0800 |
| commit | 3b2894c967377a49be084b9b39b21b2315bd9b2c (patch) | |
| tree | 93af8b44e9e6f3cd96a896677730d034768e6891 /drivers/gpu/drm/drm_modes.c | |
| parent | 446425648c5d19ff7564923863538e9fae93e916 (diff) | |
drm/modes: replace deprecated strncpy with strscpy_pad
`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 should NUL-pad as there are full struct copies happening in places:
| struct drm_mode_modeinfo umode;
|
| ...
| struct drm_property_blob *blob;
|
| drm_mode_convert_to_umode(&umode, mode);
| blob = drm_property_create_blob(crtc->dev,
| sizeof(umode), &umode);
A suitable replacement is `strscpy_pad` due to the fact that it
guarantees both NUL-termination and NUL-padding on the destination
buffer.
Additionally, replace size macro `DRM_DISPLAY_MODE_LEN` with sizeof() to
more directly tie the maximum buffer size to the destination buffer:
| struct drm_display_mode {
| ...
| char name[DRM_DISPLAY_MODE_LEN];
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
Cc: Xu Panda <xu.panda@zte.com.cn>
Signed-off-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20231016-strncpy-drivers-gpu-drm-drm_modes-c-v2-1-d0b60686e1c6@google.com
Signed-off-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'drivers/gpu/drm/drm_modes.c')
| -rw-r--r-- | drivers/gpu/drm/drm_modes.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c index ac9a406250c5..893f52ee4926 100644 --- a/drivers/gpu/drm/drm_modes.c +++ b/drivers/gpu/drm/drm_modes.c @@ -2617,8 +2617,7 @@ void drm_mode_convert_to_umode(struct drm_mode_modeinfo *out, break; } - strncpy(out->name, in->name, DRM_DISPLAY_MODE_LEN); - out->name[DRM_DISPLAY_MODE_LEN-1] = 0; + strscpy_pad(out->name, in->name, sizeof(out->name)); } /** @@ -2659,8 +2658,7 @@ int drm_mode_convert_umode(struct drm_device *dev, * useful for the kernel->userspace direction anyway. */ out->type = in->type & DRM_MODE_TYPE_ALL; - strncpy(out->name, in->name, DRM_DISPLAY_MODE_LEN); - out->name[DRM_DISPLAY_MODE_LEN-1] = 0; + strscpy_pad(out->name, in->name, sizeof(out->name)); /* Clearing picture aspect ratio bits from out flags, * as the aspect-ratio information is not stored in |