diff options
| author | Wei Chen | 2023-03-13 09:50:08 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2023-06-09 10:34:11 +0200 |
| commit | 5d2923fb0b72b09ef06888f18a1a17f756a7e7be (patch) | |
| tree | 957468d7400b2b2dd4346cfa1a59a549d014e32b /drivers/media/usb | |
| parent | 6906e613e6b7db2fd969167e9ff2090a205732d2 (diff) | |
media: dvb-usb: digitv: fix null-ptr-deref in digitv_i2c_xfer()
[ Upstream commit 9ded5bd2a49ce3015b7c936743eec0a0e6e11f0c ]
In digitv_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 digitv_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/20230313095008.1039689-1-harperchen1110@gmail.com
Signed-off-by: Wei Chen <harperchen1110@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/media/usb')
| -rw-r--r-- | drivers/media/usb/dvb-usb/digitv.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/media/usb/dvb-usb/digitv.c b/drivers/media/usb/dvb-usb/digitv.c index 2756815a780b..32134be16914 100644 --- a/drivers/media/usb/dvb-usb/digitv.c +++ b/drivers/media/usb/dvb-usb/digitv.c @@ -63,6 +63,10 @@ static int digitv_i2c_xfer(struct i2c_adapter *adap,struct i2c_msg msg[],int num warn("more than 2 i2c messages at a time is not handled yet. TODO."); for (i = 0; i < num; i++) { + if (msg[i].len < 1) { + i = -EOPNOTSUPP; + break; + } /* write/read request */ if (i+1 < num && (msg[i+1].flags & I2C_M_RD)) { if (digitv_ctrl_msg(d, USB_READ_COFDM, msg[i].buf[0], NULL, 0, |