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

From: Azeem Shaikh
Date: Mon May 22 2023 - 11:51:33 EST


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@xxxxxxxxx>
---
drivers/gpu/drm/display/drm_dp_helper.c | 2 +-
drivers/gpu/drm/display/drm_dp_mst_topology.c | 2 +-
drivers/gpu/drm/drm_mipi_dsi.c | 2 +-
3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/display/drm_dp_helper.c b/drivers/gpu/drm/display/drm_dp_helper.c
index 16565a0a5da6..e6a78fd32380 100644
--- 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 38dab76ae69e..8f7403149b2b 100644
--- 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 3fd6c733ff4e..6252ac01e945 100644
--- 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) {