media: az6007: Fix null-ptr-deref in az6007_i2c_xfer()

[ Upstream commit 1047f93430 ]

In az6007_i2c_xfer, msg is controlled by user. When msg[i].buf
is null and msg[i].len is zero, former checks on msg[i].buf would be
passed. Malicious data finally reach az6007_i2c_xfer. If accessing
msg[i].buf[0] without sanity check, null ptr deref would happen.
We add check on msg[i].len to prevent crash.

Similar commit:
commit 0ed554fd76
("media: dvb-usb: az6027: fix null-ptr-deref in az6027_i2c_xfer()")

Signed-off-by: Zhang Shurong <zhang_shurong@foxmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Zhang Shurong 2023-07-09 00:28:17 +08:00 committed by Greg Kroah-Hartman
parent 5975dbbb7a
commit a1110f19d4

View file

@ -788,6 +788,10 @@ static int az6007_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
if (az6007_xfer_debug)
printk(KERN_DEBUG "az6007: I2C W addr=0x%x len=%d\n",
addr, msgs[i].len);
if (msgs[i].len < 1) {
ret = -EIO;
goto err;
}
req = AZ6007_I2C_WR;
index = msgs[i].buf[0];
value = addr | (1 << 8);
@ -802,6 +806,10 @@ static int az6007_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
if (az6007_xfer_debug)
printk(KERN_DEBUG "az6007: I2C R addr=0x%x len=%d\n",
addr, msgs[i].len);
if (msgs[i].len < 1) {
ret = -EIO;
goto err;
}
req = AZ6007_I2C_RD;
index = msgs[i].buf[0];
value = addr;