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| author | Zhang Shurong <zhang_shurong@foxmail.com> | 2023-05-07 15:52:47 +0100 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@kernel.org> | 2023-05-14 06:30:03 +0100 |
| commit | aa4a447b81b84f69c1a89ad899df157f386d7636 (patch) | |
| tree | 51a5b1024a8acbbfa51c448315b8c0d5c0051df7 | |
| parent | dff919090155fb22679869e8469168f270dcd97f (diff) | |
| download | linux-aa4a447b81b84f69c1a89ad899df157f386d7636.tar.gz | |
media: dvb-usb-v2: rtl28xxu: fix null-ptr-deref in rtl28xxu_i2c_xfer
In rtl28xxu_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 rtl28xxu_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 0ed554fd769a
("media: dvb-usb: az6027: fix null-ptr-deref in az6027_i2c_xfer()")
Link: https://lore.kernel.org/linux-media/tencent_3623572106754AC2F266B316798B0F6CCA05@qq.com
Signed-off-by: Zhang Shurong <zhang_shurong@foxmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
| -rw-r--r-- | drivers/media/usb/dvb-usb-v2/rtl28xxu.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/drivers/media/usb/dvb-usb-v2/rtl28xxu.c b/drivers/media/usb/dvb-usb-v2/rtl28xxu.c index 795a012d40200..f7884bb56fccf 100644 --- a/drivers/media/usb/dvb-usb-v2/rtl28xxu.c +++ b/drivers/media/usb/dvb-usb-v2/rtl28xxu.c @@ -176,6 +176,10 @@ static int rtl28xxu_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], ret = -EOPNOTSUPP; goto err_mutex_unlock; } else if (msg[0].addr == 0x10) { + if (msg[0].len < 1 || msg[1].len < 1) { + ret = -EOPNOTSUPP; + goto err_mutex_unlock; + } /* method 1 - integrated demod */ if (msg[0].buf[0] == 0x00) { /* return demod page from driver cache */ @@ -189,6 +193,10 @@ static int rtl28xxu_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], ret = rtl28xxu_ctrl_msg(d, &req); } } else if (msg[0].len < 2) { + if (msg[0].len < 1) { + ret = -EOPNOTSUPP; + goto err_mutex_unlock; + } /* method 2 - old I2C */ req.value = (msg[0].buf[0] << 8) | (msg[0].addr << 1); req.index = CMD_I2C_RD; @@ -217,8 +225,16 @@ static int rtl28xxu_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], ret = -EOPNOTSUPP; goto err_mutex_unlock; } else if (msg[0].addr == 0x10) { + if (msg[0].len < 1) { + ret = -EOPNOTSUPP; + goto err_mutex_unlock; + } /* method 1 - integrated demod */ if (msg[0].buf[0] == 0x00) { + if (msg[0].len < 2) { + ret = -EOPNOTSUPP; + goto err_mutex_unlock; + } /* save demod page for later demod access */ dev->page = msg[0].buf[1]; ret = 0; @@ -231,6 +247,10 @@ static int rtl28xxu_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], ret = rtl28xxu_ctrl_msg(d, &req); } } else if ((msg[0].len < 23) && (!dev->new_i2c_write)) { + if (msg[0].len < 1) { + ret = -EOPNOTSUPP; + goto err_mutex_unlock; + } /* method 2 - old I2C */ req.value = (msg[0].buf[0] << 8) | (msg[0].addr << 1); req.index = CMD_I2C_WR; |