i2cdev_ioctl_rdwr() allocates i2c_msg.buf using memdup_user(), which
returns ZERO_SIZE_PTR if i2c_msg.len is zero.
Currently i2cdev_ioctl_rdwr() always dereferences the buf pointer in case
of I2C_M_RD | I2C_M_RECV_LEN transfer. That causes a kernel oops in
case of zero len.
Let's check the len against zero before dereferencing buf pointer.
This issue was triggered by syzkaller.
Signed-off-by: Alexander Popov <alex.popov@linux.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
[wsa: use '< 1' instead of '!' for easier readability]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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>
Cc: stable@kernel.org
There is no code protecting i2c_dev to be freed after it is returned
from i2c_dev_get_by_minor() and using it to access the value which we
already have (minor) isn't safe really.
Avoid using it and get the adapter directly from 'minor'.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Tested-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The call to put_i2c_dev() frees "i2c_dev" so there is a use after
free when we call cdev_del(&i2c_dev->cdev).
Fixes: d6760b14d4 ('i2c: dev: switch from register_chrdev to cdev API')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
I stumbled multiple times over 'return_i2c_dev', especially before the
actual 'return res'. It makes the code hard to read, so reanme the
function to 'put_i2c_dev' which also better matches 'get_free_i2c_dev'.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
i2c-dev had never moved away from the older register_chrdev interface to
implement its char device registration. The register_chrdev API has the
limitation of enabling only up to 256 i2c-dev busses to exist.
Large platforms with lots of i2c devices (i.e. pluggable transceivers)
with dedicated busses may have to exceed that limit.
In particular, there are also platforms making use of the i2c bus
multiplexing API, which instantiates a virtual bus for each possible
multiplexed selection.
This patch removes the register_chrdev usage and replaces it with the
less old cdev API, which takes away the 256 i2c-dev bus limitation.
It should not have any other impact for i2c bus drivers or user space.
This patch has been tested on qemu x86 and qemu powerpc platforms with
the aid of a module which adds and removes 5000 virtual i2c busses, as
well as validated on an existing powerpc hardware platform which makes
use of the i2c bus multiplexing API.
i2c-dev busses with device minor numbers larger than 256 have also been
validated to work with the existing i2c-tools.
Signed-off-by: Erico Nunes <erico.nunes@datacom.ind.br>
[wsa: kept includes sorted]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The first part of the comment is wrong since November 2007, delete it.
The second part of the comment is related to I2C_PEC, not I2C_SLAVE, so
move it where it belongs.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The ioctl is named I2C_RDWR for "I2C read/write". But references to it
were misspelled "rdrw". Fix them.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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>
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>
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>
Add multiplexed bus core support. I2C multiplexer and switches
like pca954x get instantiated as new adapters per port.
Signed-off-by: Michael Lawnick <ml.lawnick@gmx.de>
Acked-by: Rodolfo Giometti <giometti@linux.it>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Use memdup_user when user data is immediately copied into the allocated
region. Note that in the second case, the ++i is no longer necessary, as
the last value is already freed if needed by the call to memdup_user.
The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
expression from,to,size,flag;
position p;
identifier l1,l2;
@@
- to = \(kmalloc@p\|kzalloc@p\)(size,flag);
+ to = memdup_user(from,size);
if (
- to==NULL
+ IS_ERR(to)
|| ...) {
<+... when != goto l1;
- -ENOMEM
+ PTR_ERR(to)
...+>
}
- if (copy_from_user(to, from, size) != 0) {
- <+... when != goto l2;
- -EFAULT
- ...+>
- }
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Kees Cook
Alexander Popov
Wolfram Sang
Al Viro
Vlad Tsyrklevich
viresh kumar
Dan Carpenter
Wolfram Sang
Erico Nunes
Jean Delvare
Guenter Roeck
Jean Delvare
Thomas Meyer
Shubhrajyoti D
Michael Lawnick
Julia Lawall
Joe Perches
Farid Hammane