From: Du Cheng <ducheng2@xxxxxxxxx> commit 01faae5193d6190b7b3aa93dae43f514e866d652 upstream. add null-check on function pointer before dereference on ops->cursor Reported-by: syzbot+b67aaae8d3a927f68d20@xxxxxxxxxxxxxxxxxxxxxxxxx Cc: stable <stable@xxxxxxxxxxxxxxx> Signed-off-by: Du Cheng <ducheng2@xxxxxxxxx> Link: https://lore.kernel.org/r/20210312081421.452405-1-ducheng2@xxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/video/fbdev/core/fbcon.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/video/fbdev/core/fbcon.c +++ b/drivers/video/fbdev/core/fbcon.c @@ -1284,6 +1284,9 @@ static void fbcon_cursor(struct vc_data 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)); }
