linux-kernel - [PATCH 4.19 116/287] HID: cp2112: prevent a buffer overflow in cp2112

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: <20220823080104.297228396@linuxfoundation.org>
Date:   Tue, 23 Aug 2022 10:24:45 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org,
        Harshit Mogalapalli <harshit.m.mogalapalli@...cle.com>,
        Jiri Kosina <jkosina@...e.cz>, Sasha Levin <sashal@...nel.org>
Subject: [PATCH 4.19 116/287] HID: cp2112: prevent a buffer overflow in cp2112_xfer()

From: Harshit Mogalapalli <harshit.m.mogalapalli@...cle.com>

[ Upstream commit 381583845d19cb4bd21c8193449385f3fefa9caf ]

Smatch warnings:
drivers/hid/hid-cp2112.c:793 cp2112_xfer() error: __memcpy()
'data->block[1]' too small (33 vs 255)
drivers/hid/hid-cp2112.c:793 cp2112_xfer() error: __memcpy() 'buf' too
small (64 vs 255)

The 'read_length' variable is provided by 'data->block[0]' which comes
from user and it(read_length) can take a value between 0-255. Add an
upper bound to 'read_length' variable to prevent a buffer overflow in
memcpy().

Fixes: 542134c0375b ("HID: cp2112: Fix I2C_BLOCK_DATA transactions")
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@...cle.com>
Signed-off-by: Jiri Kosina <jkosina@...e.cz>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/hid/hid-cp2112.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/hid/hid-cp2112.c b/drivers/hid/hid-cp2112.c
index 6f65f5257236..637a7ce281c6 100644
--- a/drivers/hid/hid-cp2112.c
+++ b/drivers/hid/hid-cp2112.c
@@ -794,6 +794,11 @@ static int cp2112_xfer(struct i2c_adapter *adap, u16 addr,
 		data->word = le16_to_cpup((__le16 *)buf);
 		break;
 	case I2C_SMBUS_I2C_BLOCK_DATA:
+		if (read_length > I2C_SMBUS_BLOCK_MAX) {
+			ret = -EINVAL;
+			goto power_normal;
+		}
+
 		memcpy(data->block + 1, buf, read_length);
 		break;
 	case I2C_SMBUS_BLOCK_DATA:
-- 
2.35.1