linux-kernel - [PATCH v4] media: gspca: UBSAN: shift-out-of-bounds in set

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>] [day] [month] [year] [list]

Message-Id: <20230825130450.5287-1-coolrrsh@gmail.com>
Date:   Fri, 25 Aug 2023 18:34:50 +0530
From:   coolrrsh@...il.com
To:     hverkuil@...all.nl, mchehab@...nel.org, slark_xiao@....com,
        linux-media@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     linux-kernel-mentees@...ts.linuxfoundation.org,
        Rajeshwar R Shinde <coolrrsh@...il.com>,
        syzbot+e27f3dbdab04e43b9f73@...kaller.appspotmail.com
Subject: [PATCH v4] media: gspca: UBSAN: shift-out-of-bounds in set_flicker

From: Rajeshwar R Shinde <coolrrsh@...il.com>

Syzkaller reported the following issue:

UBSAN: shift-out-of-bounds in drivers/media/usb/gspca/cpia1.c:1031:27
shift exponent 245 is too large for 32-bit type 'int'
When the value of the variable "sd->params.exposure.gain" exceeds the
number of bits in an int, a shift-out-of-bounds error occurs. The error is
generated when the variable "currentexp" is left-shifted by more than 31
bits. In order to confirm the range is valid, the conditional expression
was added.

Reported-by: syzbot+e27f3dbdab04e43b9f73@...kaller.appspotmail.com
Closes: https://lore.kernel.org/all/20230818164522.12806-1-coolrrsh@gmail.com
Link: https://syzkaller.appspot.com/bug?extid=e27f3dbdab04e43b9f73
Signed-off-by: Rajeshwar R Shinde <coolrrsh@...il.com>
---
v1->v2
Changed the patch. Instead of avoiding shift operation for invalid
input of 'exposure.gain', throw an error for invalid range.
v2->v3
Changed the commit message details
v3->v4
Removed the trailing spaces in commit message
---
 drivers/media/usb/gspca/cpia1.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/media/usb/gspca/cpia1.c b/drivers/media/usb/gspca/cpia1.c
index 46ed95483e22..dafc522d5e7b 100644
--- a/drivers/media/usb/gspca/cpia1.c
+++ b/drivers/media/usb/gspca/cpia1.c
@@ -1028,6 +1028,8 @@ static int set_flicker(struct gspca_dev *gspca_dev, int on, int apply)
 			sd->params.exposure.expMode = 2;
 			sd->exposure_status = EXPOSURE_NORMAL;
 		}
+		if (sd->params.exposure.gain > 31)
+			return -EINVAL;
 		currentexp = currentexp << sd->params.exposure.gain;
 		sd->params.exposure.gain = 0;
 		/* round down current exposure to nearest value */
-- 
2.25.1