While fuzzing with Syzkaller, a persistent `schedule_timeout: wrong
timeout value` warning was observed, accompanied by SMBus controller
state machine corruption.
The I2C_TIMEOUT ioctl accepts a user-provided timeout in multiples of
10 ms. The user argument is checked against INT_MAX, but it is
subsequently multiplied by 10 before being passed to msecs_to_jiffies().
A malicious user can pass a large value (e.g., 429496729) that passes
the `arg > INT_MAX` check but overflows when multiplied by 10. This
results in a truncated 32-bit unsigned value that bypasses the
internal `(int)m < 0` check in `msecs_to_jiffies()`.
The truncated value is then assigned to `client->adapter->timeout`
(a signed 32-bit int), which is reinterpreted as a negative number.
When passed to wait_for_completion_timeout(), this negative value
undergoes sign extension to a 64-bit unsigned long, triggering the
`schedule_timeout` warning and causing premature returns. This leaves
the SMBus state machine in an unrecoverable state, constituting a
local Denial of Service (DoS).
Fix this by bounding the user argument to `INT_MAX / 10`.
Signed-off-by: Mingyu Wang <25181214217@stu.xidian.edu.cn>
[wsa: move the comment as well]
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
This converts some of the visually simpler cases that have been split
over multiple lines. I only did the ones that are easy to verify the
resulting diff by having just that final GFP_KERNEL argument on the next
line.
Somebody should probably do a proper coccinelle script for this, but for
me the trivial script actually resulted in an assertion failure in the
middle of the script. I probably had made it a bit _too_ trivial.
So after fighting that far a while I decided to just do some of the
syntactically simpler cases with variations of the previous 'sed'
scripts.
The more syntactically complex multi-line cases would mostly really want
whitespace cleanup anyway.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
Early return in i2cdev_ioctl_rdwr() failed to free the memory allocated
by the caller. Move freeing the memory to the function where it has been
allocated to prevent similar leaks in the future.
Fixes: 97ca843f6a ("i2c: dev: Check for I2C_FUNC_I2C before calling i2c_transfer")
Signed-off-by: Igor Pylypiv <ipylypiv@google.com>
[wsa: replaced '== NULL' with '!']
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
no_llseek had been defined to NULL two years ago, in commit 868941b144
("fs: remove no_llseek")
To quote that commit,
At -rc1 we'll need do a mechanical removal of no_llseek -
git grep -l -w no_llseek | grep -v porting.rst | while read i; do
sed -i '/\<no_llseek\>/d' $i
done
would do it.
Unfortunately, that hadn't been done. Linus, could you do that now, so
that we could finally put that thing to rest? All instances are of the
form
.llseek = no_llseek,
so it's obviously safe.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It is good practice to check that the underlying adapter supports
I2C transfers before attempting them. The i2c core would eventually
return an error, but it's more efficient to fail early.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
i2c-dev.c utilizes memdup_user() to copy a userspace array. This is done
without an overflow check.
Use the new wrapper memdup_array_user() to copy the array more safely.
Suggested-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Now that the driver core allows for struct class to be in read-only
memory, move the i2c_dev_class structure to be declared at build time
placing it into read-only memory, instead of having to be dynamically
allocated at boot time.
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
We need the fixes in here for testing, as well as the driver core
changes for documentation updates to build on.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The i2cdev_{at,de}tach_adapter() callbacks are used for two purposes:
1. As notifier callbacks, when (un)registering I2C adapters created or
destroyed after i2c_dev_init(),
2. As bus iterator callbacks, for registering already existing
adapters from i2c_dev_init(), and for cleanup.
Unfortunately both use cases expect different return values: the former
expects NOTIFY_* return codes, while the latter expects zero or error
codes, and aborts in case of error.
Hence in case 2, as soon as i2cdev_{at,de}tach_adapter() returns
(non-zero) NOTIFY_OK, the bus iterator aborts. This causes (a) only the
first already existing adapter to be registered, leading to missing
/dev/i2c-* entries, and (b) a failure to unregister all but the first
I2C adapter during cleanup.
Fix this by introducing separate callbacks for the bus iterator,
wrapping the notifier functions, and always returning succes.
Any errors inside these callback functions are unlikely to happen, and
are fatal anyway.
Fixes: cddf70d0bc ("i2c: dev: fix notifier return values")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
We have a set of return values that notifier callbacks can return. They
should not return 0, error codes or anything other than those predefined
values. Make the i2c character device's callback return NOTIFY_DONE or
NOTIFY_OK depending on the situation.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Sparse has warned us about wrong address space for user pointers:
i2c-dev.c:561:50: warning: incorrect type in initializer (different address spaces)
i2c-dev.c:561:50: expected unsigned char [usertype] *buf
i2c-dev.c:561:50: got void [noderef] __user *
Force cast the pointer to (__u8 *) that is used by I²C core code.
Note, this is an additional fix to the previously addressed similar issue
in the I2C_RDWR case in the same function.
Fixes: 3265a7e6b4 ("i2c: dev: Add __user annotation")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
If dev_set_name() fails, the dev_name() is null, check the return
value of dev_set_name() to avoid the null-ptr-deref.
Fixes: 1413ef638a ("i2c: dev: Fix the race between the release of i2c_dev and cdev")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Wrong user data may cause warning in i2c_transfer(), ex: zero msgs.
Userspace should not be able to trigger warnings, so this patch adds
validation checks for user data in compact ioctl to prevent reported
warnings
Reported-and-tested-by: syzbot+e417648b303855b91d8a@syzkaller.appspotmail.com
Fixes: 7d5cb45655 ("i2c compat ioctls: move to ->compat_ioctl()")
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Pull i2c updates from Wolfram Sang:
"I2C has a smaller pull reuest this time:
- new driver for I2C virtio
- removal of PMC SMP driver because platform is already gone
- IRQ probing and DMAENGINE API cleanups
- add SI metric prefix definitions to units.h
- beginning of i801 refactorization
- a few driver improvements"
* 'i2c/for-mergewindow' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (28 commits)
i2c: cadence: Implement save restore
i2c: xlp9xx: fix main IRQ check
i2c: mt65xx: fix IRQ check
i2c: virtio: add a virtio i2c frontend driver
i2c: hix5hd2: fix IRQ check
i2c: s3c2410: fix IRQ check
i2c: iop3xx: fix deferred probing
i2c: synquacer: fix deferred probing
i2c: sun6i-pw2i: Prefer strscpy over strlcpy
i2c: remove dead PMC MSP TWI/SMBus/I2C driver
i2c: dev: Use sysfs_emit() in "show" functions
i2c: dev: Define pr_fmt() and drop duplication substrings
i2c: designware: Fix indentation in the header
i2c: designware: Use DIV_ROUND_CLOSEST() macro
units: Add SI metric prefix definitions
i2c: at91: mark PM ops as __maybe unused
i2c: sh_mobile: : use proper DMAENGINE API for termination
i2c: qup: : use proper DMAENGINE API for termination
i2c: mxs: : use proper DMAENGINE API for termination
i2c: imx: : use proper DMAENGINE API for termination
...
The sysfs_emit() function was introduced to make it less ambiguous
which function is preferred when writing to the output buffer in
a "show" callback [1].
Convert the I²C device sysfs interface from sprintf() to sysfs_emit()
accordingly, as the latter is aware of the PAGE_SIZE buffer and correctly
returns the number of bytes written into the buffer.
No functional change intended.
[1] Documentation/filesystems/sysfs.rst
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Define pr_fmt() to print module name as prefix and at the same time
drop duplication substrings in the messages.
While at it, convert printk(<LEVEL>) to pr_<level>().
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
If an i2c driver happens to not provide the full amount of data that a
user asks for, it is possible that some uninitialized data could be sent
to userspace. While all in-kernel drivers look to be safe, just be sure
by initializing the buffer to zero before it is passed to the i2c driver
so that any future drivers will not have this issue.
Also properly copy the amount of data recvieved to the userspace buffer,
as pointed out by Dan Carpenter.
Reported-by: Eric Dumazet <edumazet@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Fix Sparse warnings:
drivers/i2c/i2c-dev.c:546:19: warning: incorrect type in assignment (different address spaces)
drivers/i2c/i2c-dev.c:549:53: warning: incorrect type in argument 2 (different address spaces)
compat_ptr() returns a pointer tagged __user which gets assigned to a
pointer missing the __user annotation. The same pointer is passed to
copy_from_user() as an argument where it is expected to have the __user
annotation. Fix both by adding the __user annotation to the pointer.
Fixes: 7d5cb45655 ("i2c compat ioctls: move to ->compat_ioctl()")
Signed-off-by: Andreas Hecht <andreas.e.hecht@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Modules with multiple authors should use multiple MODULE_AUTHOR()
statements according to comment in include/linux/module.h.
Split the i2c modules with multiple authors to use multiple
MODULE_AUTHOR() statements.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
The struct cdev is embedded in the struct i2c_dev. In the current code,
we would free the i2c_dev struct directly in put_i2c_dev(), but the
cdev is manged by a kobject, and the release of it is not predictable.
So it is very possible that the i2c_dev is freed before the cdev is
entirely released. We can easily get the following call trace with
CONFIG_DEBUG_KOBJECT_RELEASE and CONFIG_DEBUG_OBJECTS_TIMERS enabled.
ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x38
WARNING: CPU: 19 PID: 1 at lib/debugobjects.c:325 debug_print_object+0xb0/0xf0
Modules linked in:
CPU: 19 PID: 1 Comm: swapper/0 Tainted: G W 5.2.20-yocto-standard+ #120
Hardware name: Marvell OcteonTX CN96XX board (DT)
pstate: 80c00089 (Nzcv daIf +PAN +UAO)
pc : debug_print_object+0xb0/0xf0
lr : debug_print_object+0xb0/0xf0
sp : ffff00001292f7d0
x29: ffff00001292f7d0 x28: ffff800b82151788
x27: 0000000000000001 x26: ffff800b892c0000
x25: ffff0000124a2558 x24: 0000000000000000
x23: ffff00001107a1d8 x22: ffff0000116b5088
x21: ffff800bdc6afca8 x20: ffff000012471ae8
x19: ffff00001168f2c8 x18: 0000000000000010
x17: 00000000fd6f304b x16: 00000000ee79de43
x15: ffff800bc0e80568 x14: 79616c6564203a74
x13: 6e6968207473696c x12: 5f72656d6974203a
x11: ffff0000113f0018 x10: 0000000000000000
x9 : 000000000000001f x8 : 0000000000000000
x7 : ffff0000101294cc x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000001
x3 : 00000000ffffffff x2 : 0000000000000000
x1 : 387fc15c8ec0f200 x0 : 0000000000000000
Call trace:
debug_print_object+0xb0/0xf0
__debug_check_no_obj_freed+0x19c/0x228
debug_check_no_obj_freed+0x1c/0x28
kfree+0x250/0x440
put_i2c_dev+0x68/0x78
i2cdev_detach_adapter+0x60/0xc8
i2cdev_notifier_call+0x3c/0x70
notifier_call_chain+0x8c/0xe8
blocking_notifier_call_chain+0x64/0x88
device_del+0x74/0x380
device_unregister+0x54/0x78
i2c_del_adapter+0x278/0x2d0
unittest_i2c_bus_remove+0x3c/0x80
platform_drv_remove+0x30/0x50
device_release_driver_internal+0xf4/0x1c0
driver_detach+0x58/0xa0
bus_remove_driver+0x84/0xd8
driver_unregister+0x34/0x60
platform_driver_unregister+0x20/0x30
of_unittest_overlay+0x8d4/0xbe0
of_unittest+0xae8/0xb3c
do_one_initcall+0xac/0x450
do_initcall_level+0x208/0x224
kernel_init_freeable+0x2d8/0x36c
kernel_init+0x18/0x108
ret_from_fork+0x10/0x1c
irq event stamp: 3934661
hardirqs last enabled at (3934661): [<ffff00001009fa04>] debug_exception_exit+0x4c/0x58
hardirqs last disabled at (3934660): [<ffff00001009fb14>] debug_exception_enter+0xa4/0xe0
softirqs last enabled at (3934654): [<ffff000010081d94>] __do_softirq+0x46c/0x628
softirqs last disabled at (3934649): [<ffff0000100b4a1c>] irq_exit+0x104/0x118
This is a common issue when using cdev embedded in a struct.
Fortunately, we already have a mechanism to solve this kind of issue.
Please see commit 233ed09d7f ("chardev: add helper function to
register char devs with a struct device") for more detail.
In this patch, we choose to embed the struct device into the i2c_dev,
and use the API provided by the commit 233ed09d7f to make sure that
the release of i2c_dev and cdev are in sequence.
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
