linux-kernel - [PATCH 4.9 200/222] fbdev: sbuslib: integer overflow in sbusfb_ioctl

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20191122100916.671409720@linuxfoundation.org>
Date:   Fri, 22 Nov 2019 11:29:00 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Dan Carpenter <dan.carpenter@...cle.com>,
        Peter Malone <peter.malone@...il.com>,
        Philippe Ombredanne <pombredanne@...b.com>,
        Mathieu Malaterre <malat@...ian.org>,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 4.9 200/222] fbdev: sbuslib: integer overflow in sbusfb_ioctl_helper()

From: Dan Carpenter <dan.carpenter@...cle.com>

[ Upstream commit e5017716adb8aa5c01c52386c1b7470101ffe9c5 ]

The "index + count" addition can overflow.  Both come directly from the
user.  This bug leads to an information leak.

Signed-off-by: Dan Carpenter <dan.carpenter@...cle.com>
Cc: Peter Malone <peter.malone@...il.com>
Cc: Philippe Ombredanne <pombredanne@...b.com>
Cc: Mathieu Malaterre <malat@...ian.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/video/fbdev/sbuslib.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/video/fbdev/sbuslib.c b/drivers/video/fbdev/sbuslib.c
index b425718925c01..52e161dbd2047 100644
--- a/drivers/video/fbdev/sbuslib.c
+++ b/drivers/video/fbdev/sbuslib.c
@@ -170,7 +170,7 @@ int sbusfb_ioctl_helper(unsigned long cmd, unsigned long arg,
 		    get_user(ublue, &c->blue))
 			return -EFAULT;
 
-		if (index + count > cmap->len)
+		if (index > cmap->len || count > cmap->len - index)
 			return -EINVAL;
 
 		for (i = 0; i < count; i++) {
-- 
2.20.1