drm/display/dp_mst: Replace all non-returning strlcpy with strscpy

strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy() here with strscpy().
No return values were used, so direct replacement is safe.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89

Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230522155124.2336545-1-azeemshaikh38@gmail.com

diff --git a/drivers/gpu/drm/display/drm_dp_helper.c b/drivers/gpu/drm/display/drm_dp_helper.c
index 16565a0a5da6d98d1001cfd3acb9cd547e73b105..e6a78fd32380a1e73d58ecd4f5f4221ec5b599db 100644 (file)
--- a/drivers/gpu/drm/display/drm_dp_helper.c
+++ b/drivers/gpu/drm/display/drm_dp_helper.c
@@ -2103,7 +2103,7 @@ int drm_dp_aux_register(struct drm_dp_aux *aux)
        aux->ddc.owner = THIS_MODULE;
        aux->ddc.dev.parent = aux->dev;
 
-       strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
+       strscpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
                sizeof(aux->ddc.name));
 
        ret = drm_dp_aux_register_devnode(aux);

diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c
index 38dab76ae69ea6232062be9b431d52a57ed4015c..8f7403149b2bd8a55eacd92f4094503f4b6999ec 100644 (file)
--- a/drivers/gpu/drm/display/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c
@@ -5702,7 +5702,7 @@ static int drm_dp_mst_register_i2c_bus(struct drm_dp_mst_port *port)
        aux->ddc.dev.parent = parent_dev;
        aux->ddc.dev.of_node = parent_dev->of_node;
 
-       strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(parent_dev),
+       strscpy(aux->ddc.name, aux->name ? aux->name : dev_name(parent_dev),
                sizeof(aux->ddc.name));
 
        return i2c_add_adapter(&aux->ddc);

diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c
index 3fd6c733ff4e344f60bfcccf49bacc8d003ea1dc..6252ac01e945a65a056e46d397f018b667ed57ea 100644 (file)
--- a/drivers/gpu/drm/drm_mipi_dsi.c
+++ b/drivers/gpu/drm/drm_mipi_dsi.c
@@ -223,7 +223,7 @@ mipi_dsi_device_register_full(struct mipi_dsi_host *host,
 
        device_set_node(&dsi->dev, of_fwnode_handle(info->node));
        dsi->channel = info->channel;
-       strlcpy(dsi->name, info->type, sizeof(dsi->name));
+       strscpy(dsi->name, info->type, sizeof(dsi->name));
 
        ret = mipi_dsi_device_add(dsi);
        if (ret) {