From 050b074e228523d239e47576606be3c0de5dfa00 Mon Sep 17 00:00:00 2001 From: Adam Borowski Date: Sat, 3 Jun 2017 09:35:06 +0200 Subject: [PATCH] vt: fix unchecked __put_user() in tioclinux ioctls commit 6987dc8a70976561d22450b5858fc9767788cc1c upstream. Only read access is checked before this call. Actually, at the moment this is not an issue, as every in-tree arch does the same manual checks for VERIFY_READ vs VERIFY_WRITE, relying on the MMU to tell them apart, but this wasn't the case in the past and may happen again on some odd arch in the future. If anyone cares about 3.7 and earlier, this is a security hole (untested) on real 80386 CPUs. Signed-off-by: Adam Borowski Signed-off-by: Greg Kroah-Hartman --- drivers/tty/vt/vt.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c index 5ab54ef4f304..e4f69bddcfb1 100644 --- a/drivers/tty/vt/vt.c +++ b/drivers/tty/vt/vt.c @@ -2708,13 +2708,13 @@ int tioclinux(struct tty_struct *tty, unsigned long arg) * related to the kernel should not use this. */ data = vt_get_shift_state(); - ret = __put_user(data, p); + ret = put_user(data, p); break; case TIOCL_GETMOUSEREPORTING: console_lock(); /* May be overkill */ data = mouse_reporting(); console_unlock(); - ret = __put_user(data, p); + ret = put_user(data, p); break; case TIOCL_SETVESABLANK: console_lock(); @@ -2723,7 +2723,7 @@ int tioclinux(struct tty_struct *tty, unsigned long arg) break; case TIOCL_GETKMSGREDIRECT: data = vt_get_kmsg_redirect(); - ret = __put_user(data, p); + ret = put_user(data, p); break; case TIOCL_SETKMSGREDIRECT: if (!capable(CAP_SYS_ADMIN)) {