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| author | Wei Chen <harperchen1110@gmail.com> | 2023-03-13 12:50:08 +0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@kernel.org> | 2023-05-14 08:30:06 +0300 |
| commit | 9ded5bd2a49ce3015b7c936743eec0a0e6e11f0c (patch) | |
| tree | fee0471a252bb8933743cea07d4111c8a25085f7 /drivers/media/usb | |
| parent | aa4a447b81b84f69c1a89ad899df157f386d7636 (diff) | |
| download | linux-9ded5bd2a49ce3015b7c936743eec0a0e6e11f0c.tar.xz | |
media: dvb-usb: digitv: fix null-ptr-deref in digitv_i2c_xfer()
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>
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, |