[PATCH] drivers: tty: vt: vt.c: fix NULL dereference crash

From: Hassan Shahbazi
Date: Sun Mar 07 2021 - 06:00:01 EST


Fix a NULL deference crash on hiding the cursor.

Reported by: syzbot
https://syzkaller.appspot.com/bug?id=defb47bf56e1c14d5687280c7bb91ce7b608b94b

Signed-off-by: Hassan Shahbazi <h.shahbazi.git@xxxxxxxxx>
---
drivers/tty/vt/vt.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 284b07224c55..8c3e83c81341 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -904,7 +904,9 @@ static void hide_cursor(struct vc_data *vc)
if (vc_is_sel(vc))
clear_selection();

- vc->vc_sw->con_cursor(vc, CM_ERASE);
+ if (vc->vc_sw)
+ vc->vc_sw->con_cursor(vc, CM_ERASE);
+
hide_softcursor(vc);
}

--
2.26.2