[PATCH] drm/rockchip: analogix_dp: bound endpoint name formatting

[Yudi Yang]

rockchip_dp_drm_encoder_enable() uses sprintf() to format a device tree
path into a 32-byte stack buffer. Device tree paths are not limited to
this size, so a sufficiently long path can overflow the buffer.

Use snprintf() with the destination size to truncate the generated name
and keep the writes within bounds.

Fixes: 729f8eefdcad ("drm/rockchip: analogix_dp: Add support for RK3588")
Cc: stable at vger.kernel.org
Signed-off-by: Yudi Yang <2000jedi at gmail.com>
---
 drivers/gpu/drm/rockchip/analogix_dp-rockchip.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c b/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
index 587e60232ec7..efd5a98e80bd 100644
--- a/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
+++ b/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
@@ -241,10 +241,11 @@ static void rockchip_dp_drm_encoder_enable(struct drm_encoder *encoder,
 				of_graph_get_remote_port(endpoint.local_node);
 
 			of_property_read_u32(remote_port, "reg", &port_id);
-			sprintf(name, "%s vp%d", remote_port_parent->full_name, port_id);
+			snprintf(name, sizeof(name), "%s vp%d",
+				 remote_port_parent->full_name, port_id);
 		} else {
-			sprintf(name, "%s %s",
-				remote_port_parent->full_name, endpoint.id ? "vopl" : "vopb");
+			snprintf(name, sizeof(name), "%s %s",
+				 remote_port_parent->full_name, endpoint.id ? "vopl" : "vopb");
 		}
 
 		DRM_DEV_DEBUG(dp->dev, "vop %s output to dp\n", (ret) ? "LIT" : "BIG");
-- 
2.43.0