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authormatthieu castet <castet.matthieu@free.fr>2009-05-20 05:42:33 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2009-06-16 18:21:09 -0300
commit81dae6716f13e801cfe2035514e7aeb971b57492 (patch)
tree20550dc21f1efefa556f7a046b31cb32b0ac2f21
parenta9b8fe30a6d2a49749327ff18c4daa488ef73ab3 (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.c7
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);