[PATCH 5.11 148/152] drivers: video: fbcon: fix NULL dereference in fbcon_cursor()

Greg Kroah-Hartman
2021-04-05T09:24:46Z

From: Du Cheng <ducheng2@gmail.com>

commit 01faae5193d6190b7b3aa93dae43f514e866d652 upstream.

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

Reported-by: syzbot+b67aaae8d3a927f68d20@syzkaller.appspotmail.com
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Du Cheng <ducheng2@gmail.com>
Link: https://lore.kernel.org/r/20210312081421.452405-1-ducheng2@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
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
@@ -1341,6 +1341,9 @@ 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));
}