diff options
| author | matthieu castet <castet.matthieu@free.fr> | 2009-05-20 05:42:33 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2009-06-16 18:21:09 -0300 |
| commit | 81dae6716f13e801cfe2035514e7aeb971b57492 (patch) | |
| tree | 20550dc21f1efefa556f7a046b31cb32b0ac2f21 | |
| parent | a9b8fe30a6d2a49749327ff18c4daa488ef73ab3 (diff) | |
V4L/DVB (11832): dibusb_mc: fix i2c to not corrupt eeprom in case of strange read pattern
dibusb_i2c_xfer seems to do things very dangerous :
it assumes that it get only write/read request or write request.
That means that read can be understood as write. For example a program
doing
file = open("/dev/i2c-x", O_RDWR);
ioctl(file, I2C_SLAVE, 0x50)
read(file, data, 10)
will corrupt the eeprom as it will be understood as a write.
Signed-off-by: Matthieu CASTET <castet.matthieu@free.fr>
Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
| -rw-r--r-- | drivers/media/dvb/dvb-usb/dibusb-common.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/media/dvb/dvb-usb/dibusb-common.c b/drivers/media/dvb/dvb-usb/dibusb-common.c index 8ee6cd4da9e..8dbad1ec53c 100644 --- a/drivers/media/dvb/dvb-usb/dibusb-common.c +++ b/drivers/media/dvb/dvb-usb/dibusb-common.c @@ -133,14 +133,17 @@ static int dibusb_i2c_xfer(struct i2c_adapter *adap,struct i2c_msg msg[],int num for (i = 0; i < num; i++) { /* write/read request */ - if (i+1 < num && (msg[i+1].flags & I2C_M_RD)) { + if (i+1 < num && (msg[i].flags & I2C_M_RD) == 0 + && (msg[i+1].flags & I2C_M_RD)) { if (dibusb_i2c_msg(d, msg[i].addr, msg[i].buf,msg[i].len, msg[i+1].buf,msg[i+1].len) < 0) break; i++; - } else + } else if ((msg[i].flags & I2C_M_RD) == 0) { if (dibusb_i2c_msg(d, msg[i].addr, msg[i].buf,msg[i].len,NULL,0) < 0) break; + } else + break; } mutex_unlock(&d->i2c_mutex); |