[PATCH v3] fbconsole: check cursor position before moving

[Bastian Stender]

Moving the cursor to x=2, y=2 with "\e[3;3H" on a 12x2 framebuffer
console lead to a barebox crash while drawing the cursor. If the
cursor position is out of bounds clip the cursor to the corresponding
edge.

Signed-off-by: Bastian Stender <bst at pengutronix.de>
---
 drivers/video/fbconsole.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/video/fbconsole.c b/drivers/video/fbconsole.c
index 64f7d7364e..33649c597d 100644
--- a/drivers/video/fbconsole.c
+++ b/drivers/video/fbconsole.c
@@ -264,10 +264,13 @@ static void fbc_parse_csi(struct fbc_priv *priv)
 		return;
 	case 'H':
 		video_invertchar(priv, priv->x, priv->y);
+
 		pos = simple_strtoul(priv->csi, &end, 10);
-		priv->y = pos ? pos - 1 : 0;
+		priv->y = clamp(pos - 1, 0, (int) priv->rows);
+
 		pos = simple_strtoul(end + 1, NULL, 10);
-		priv->x = pos ? pos - 1 : 0;
+		priv->x = clamp(pos - 1, 0, (int) priv->cols);
+
 		video_invertchar(priv, priv->x, priv->y);
 	case 'K':
 		pos = simple_strtoul(priv->csi, &end, 10);
-- 
2.11.0