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| author | Zhang Shurong <zhang_shurong@foxmail.com> | 2023-07-06 00:06:54 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-09-23 10:48:16 +0200 |
| commit | fa58d9db5cad4bb7bb694b6837e3b96d87554f2b (patch) | |
| tree | c11854c0ccababe2b6ae8ef7709d674cd8cca011 /drivers/media | |
| parent | 3cc4c2f6c266fe5b33a7fa797f31e8b3f06ce58c (diff) | |
| download | linux-stable-fa58d9db5cad4bb7bb694b6837e3b96d87554f2b.tar.gz linux-stable-fa58d9db5cad4bb7bb694b6837e3b96d87554f2b.tar.bz2 linux-stable-fa58d9db5cad4bb7bb694b6837e3b96d87554f2b.zip | |
media: dvb-usb-v2: af9035: Fix null-ptr-deref in af9035_i2c_master_xfer
[ Upstream commit 7bf744f2de0a848fb1d717f5831b03db96feae89 ]
In af9035_i2c_master_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 af9035_i2c_master_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()")
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>
[ moved variable declaration to fix build issues in older kernels - gregkh ]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/media')
| -rw-r--r-- | drivers/media/usb/dvb-usb-v2/af9035.c | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/drivers/media/usb/dvb-usb-v2/af9035.c b/drivers/media/usb/dvb-usb-v2/af9035.c index 1f6c1eefe389..8a83f27875ec 100644 --- a/drivers/media/usb/dvb-usb-v2/af9035.c +++ b/drivers/media/usb/dvb-usb-v2/af9035.c @@ -284,6 +284,7 @@ static int af9035_i2c_master_xfer(struct i2c_adapter *adap, struct dvb_usb_device *d = i2c_get_adapdata(adap); struct state *state = d_to_priv(d); int ret; + u32 reg; if (mutex_lock_interruptible(&d->i2c_mutex) < 0) return -EAGAIN; @@ -336,8 +337,10 @@ static int af9035_i2c_master_xfer(struct i2c_adapter *adap, ret = -EOPNOTSUPP; } else if ((msg[0].addr == state->af9033_i2c_addr[0]) || (msg[0].addr == state->af9033_i2c_addr[1])) { + if (msg[0].len < 3 || msg[1].len < 1) + return -EOPNOTSUPP; /* demod access via firmware interface */ - u32 reg = msg[0].buf[0] << 16 | msg[0].buf[1] << 8 | + reg = msg[0].buf[0] << 16 | msg[0].buf[1] << 8 | msg[0].buf[2]; if (msg[0].addr == state->af9033_i2c_addr[1]) @@ -395,17 +398,16 @@ static int af9035_i2c_master_xfer(struct i2c_adapter *adap, ret = -EOPNOTSUPP; } else if ((msg[0].addr == state->af9033_i2c_addr[0]) || (msg[0].addr == state->af9033_i2c_addr[1])) { + if (msg[0].len < 3) + return -EOPNOTSUPP; /* demod access via firmware interface */ - u32 reg = msg[0].buf[0] << 16 | msg[0].buf[1] << 8 | + reg = msg[0].buf[0] << 16 | msg[0].buf[1] << 8 | msg[0].buf[2]; if (msg[0].addr == state->af9033_i2c_addr[1]) reg |= 0x100000; - ret = (msg[0].len >= 3) ? af9035_wr_regs(d, reg, - &msg[0].buf[3], - msg[0].len - 3) - : -EOPNOTSUPP; + ret = af9035_wr_regs(d, reg, &msg[0].buf[3], msg[0].len - 3); } else { /* I2C write */ u8 buf[MAX_XFER_SIZE]; |