[PATCH] drivers: video: fbcon: fix NULL dereference in fbcon_cursor()

[Du Cheng]

add null-check on function pointer before dereference on ops->cursor

Reported-by: syzbot+b67aaae8d3a927f68d20 at syzkaller.appspotmail.com
Signed-off-by: Du Cheng <ducheng2 at gmail.com>
---
 drivers/video/fbdev/core/fbcon.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
index 44a5cd2f54cc..3406067985b1 100644
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -1333,6 +1333,9 @@ static void fbcon_cursor(struct vc_data *vc, int mode)
 
 	ops->cursor_flash = (mode == CM_ERASE) ? 0 : 1;
 
+	if (!ops->cursor)
+		return;
+
 	ops->cursor(vc, info, mode, get_color(vc, info, c, 1),
 		    get_color(vc, info, c, 0));
 }
-- 
2.27.0