commit a0692f0eef91354b62c2b4c94954536536be5425 upstream.

If I2C_M_RECV_LEN check failed, msgs[i].buf allocated by memdup_user
will not be freed. Pump index up so it will be freed.

Fixes: 838bfa6049fb ("i2c-dev: Add support for I2C_M_RECV_LEN")
Signed-off-by: Yingjoe Chen <yingjoe.chen@mediatek.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 6ebec961d59bccf65d08b13fc1ad4e6272a89338 upstream.

If adapter->retries is set to a minus value from user space via ioctl,
it will make __i2c_transfer and __i2c_smbus_xfer skip the calling to
adapter->algo->master_xfer and adapter->algo->smbus_xfer that is
registered by the underlying bus drivers, and return value 0 to all the
callers. The bus driver will never be accessed anymore by all users,
besides, the users may still get successful return value without any
error or information log print out.

If adapter->timeout is set to minus value from user space via ioctl,
it will make the retrying loop in __i2c_transfer and __i2c_smbus_xfer
always break after the the first try, due to the time_after always
returns true.

Signed-off-by: Yi Zeng <yizeng@asrmicro.com>
[wsa: minor grammar updates to commit message]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

commit 30f939feaeee23e21391cfc7b484f012eb189c3c upstream.

i2c_smbus_xfer() does not always fill an entire block, allowing
kernel stack memory disclosure through the temp variable. Clear
it before it's read to.

Signed-off-by: Vlad Tsyrklevich <vlad@tsyrklevich.net>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

The 'name' attribute is needed for all i2c-dev class devices, meaning
it can be created automatically by pointing to it in the class data
structure. This simplifies the code and reduces the probability for race
conditions (the name attribute should exist by the time the device is
announced to user space).

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

As the bus driver side implementation of I2C_M_RECV_LEN is heavily
tied to SMBus, we can't support received length over 32 bytes, but
let's at least support that.

In practice, the caller will have to setup a buffer large enough to
cover the case where received length byte has value 32, so minimum
32 + 1 = 33 bytes, possibly more if there is a fixed number of bytes
added for the specific slave (for example a checksum.)

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>

Signed-off-by: Jean Delvare <khali@linux-fr.org>

Use memdup_user rather than duplicating its implementation.
This is a little bit restricted to reduce false positives.

The semantic patch that makes this output is available
in scripts/coccinelle/api/memdup_user.cocci.

More information about semantic patching is available at
http://coccinelle.lip6.fr/

Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

The function i2cdev_notifier_call is used only in i2c-dev file
making it static.
Also removes the following sparse warning

drivers/i2c/i2c-dev.c:582:5: warning: symbol 'i2cdev_notifier_call'
was not declared. Should it be static?

Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

Use the standard driver core mechanism to keep track of i2c adapters
present on the system: i2c_for_each_dev and a notifier. This will let
us deprecate and ultimately remove the legacy attach_adapter and
detach_adapter callbacks in i2c_driver.

Signed-off-by: Jean Delvare <khali@linux-fr.org>