linux-stable.git/drivers/media, branch v3.18.103

media: usbtv: prevent double free in error case

2018-04-08T09:49:48+00:00

commit 50e7044535537b2a54c7ab798cd34c7f6d900bd2 upstream.

Quoting the original report:

It looks like there is a double-free vulnerability in Linux usbtv driver
on an error path of usbtv_probe function. When audio registration fails,
usbtv_video_free function ends up freeing usbtv data structure, which
gets freed the second time under usbtv_video_fail label.

usbtv_audio_fail:

        usbtv_video_free(usbtv); =>

           v4l2_device_put(&usbtv->v4l2_dev);

              => v4l2_device_put

                  => kref_put

                      => v4l2_device_release

  => usbtv_release (CALLBACK)

                             => kfree(usbtv) (1st time)

usbtv_video_fail:

        usb_set_intfdata(intf, NULL);

        usb_put_dev(usbtv->udev);

        kfree(usbtv); (2nd time)

So, as we have refcounting, use it

Reported-by: Yavuz, Tuba 
Signed-off-by: Oliver Neukum 
CC: stable@vger.kernel.org
Signed-off-by: Hans Verkuil 
Signed-off-by: Mauro Carvalho Chehab 
Signed-off-by: Greg Kroah-Hartman

media: v4l2-compat-ioctl32: initialize a reserved field

2018-04-08T09:49:47+00:00

The get_v4l2_create32() function is missing a logic with
would be cleaning a reserved field, causing v4l2-compliance
to complain:

 Buffer ioctls (Input 0):
		fail: v4l2-test-buffers.cpp(506): check_0(crbufs.reserved, sizeof(crbufs.reserved))
	test VIDIOC_REQBUFS/CREATE_BUFS/QUERYBUF: FAIL

Signed-off-by: Mauro Carvalho Chehab 
Signed-off-by: Greg Kroah-Hartman

media: v4l2-compat-ioctl32: use compat_u64 for video standard

2018-04-08T09:49:47+00:00

Instead of using the "v4l2_std_id" typedef, use compat_u64,
as otherwise it fails to properly handle some ioctls.

Signed-off-by: Mauro Carvalho Chehab 
Signed-off-by: Greg Kroah-Hartman

media: media/v4l2-ctrls: volatiles should not generate CH_VALUE

2018-04-08T09:49:47+00:00

Volatile controls should not generate CH_VALUE events.

Set has_changed to false to prevent this happening.

Signed-off-by: Ricardo Ribalda Delgado 
Signed-off-by: Hans Verkuil 
Signed-off-by: Mauro Carvalho Chehab 
Signed-off-by: Mauro Carvalho Chehab 
Signed-off-by: Greg Kroah-Hartman

media: v4l2-ctrls: fix sparse warning

2018-04-08T09:49:47+00:00

The warning is simple:

drivers/media/v4l2-core/v4l2-ctrls.c:1685:15: warning: incorrect type in assignment (different address spaces)

but the fix isn't.

The core problem was that the conversion from user to kernelspace was
done at too low a level and that needed to be moved up. That made it possible
to drop pointers to v4l2_ext_control from set_ctrl and validate_new and
clean up this sparse warning because those functions now always operate
on kernelspace pointers.

Signed-off-by: Hans Verkuil 
Signed-off-by: Mauro Carvalho Chehab 
Signed-off-by: Mauro Carvalho Chehab 
Signed-off-by: Greg Kroah-Hartman

media: v4l2-compat-ioctl32.c: refactor compat ioctl32 logic

2018-04-08T09:49:47+00:00

commit a1dfb4c48cc1e64eeb7800a27c66a6f7e88d075a upstream.

The 32-bit compat v4l2 ioctl handling is implemented based on its 64-bit
equivalent. It converts 32-bit data structures into its 64-bit
equivalents and needs to provide the data to the 64-bit ioctl in user
space memory which is commonly allocated using
compat_alloc_user_space().

However, due to how that function is implemented, it can only be called
a single time for every syscall invocation.

Supposedly to avoid this limitation, the existing code uses a mix of
memory from the kernel stack and memory allocated through
compat_alloc_user_space().

Under normal circumstances, this would not work, because the 64-bit
ioctl expects all pointers to point to user space memory. As a
workaround, set_fs(KERNEL_DS) is called to temporarily disable this
extra safety check and allow kernel pointers. However, this might
introduce a security vulnerability: The result of the 32-bit to 64-bit
conversion is writeable by user space because the output buffer has been
allocated via compat_alloc_user_space(). A malicious user space process
could then manipulate pointers inside this output buffer, and due to the
previous set_fs(KERNEL_DS) call, functions like get_user() or put_user()
no longer prevent kernel memory access.

The new approach is to pre-calculate the total amount of user space
memory that is needed, allocate it using compat_alloc_user_space() and
then divide up the allocated memory to accommodate all data structures
that need to be converted.

An alternative approach would have been to retain the union type karg
that they allocated on the kernel stack in do_video_ioctl(), copy all
data from user space into karg and then back to user space. However, we
decided against this approach because it does not align with other
compat syscall implementations. Instead, we tried to replicate the
get_user/put_user pairs as found in other places in the kernel:

if (get_user(clipcount, &up->clipcount) ||
put_user(clipcount, &kp->clipcount)) return -EFAULT;

Notes from hans.verkuil@cisco.com:

This patch was taken from:
https://github.com/LineageOS/android_kernel_samsung_apq8084/commit/97b733953c06e4f0398ade18850f0817778255f7

Clearly nobody could be bothered to upstream this patch or at minimum
tell us :-( We only heard about this a week ago.

This patch was rebased and cleaned up. Compared to the original I
also swapped the order of the convert_in_user arguments so that they
matched copy_in_user. It was hard to review otherwise. I also replaced
the ALLOC_USER_SPACE/ALLOC_AND_GET by a normal function.

Fixes: 6b5a9492ca ("v4l: introduce string control support.")

Signed-off-by: Daniel Mentz
Co-developed-by: Hans Verkuil
Acked-by: Sakari Ailus
Signed-off-by: Hans Verkuil
Signed-off-by: Mauro Carvalho Chehab
Signed-off-by: Sasha Levin
Signed-off-by: Greg Kroah-Hartman

media: v4l2-compat-ioctl32.c: don't copy back the result for certain errors

2018-04-08T09:49:47+00:00

commit d83a8243aaefe62ace433e4384a4f077bed86acb upstream.

Some ioctls need to copy back the result even if the ioctl returned
an error. However, don't do this for the error code -ENOTTY.
It makes no sense in that cases.

Signed-off-by: Hans Verkuil 
Acked-by: Sakari Ailus 
Signed-off-by: Mauro Carvalho Chehab 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

media: v4l2-compat-ioctl32.c: drop pr_info for unknown buffer type

2018-04-08T09:49:47+00:00

commit 169f24ca68bf0f247d111aef07af00dd3a02ae88 upstream.

There is nothing wrong with using an unknown buffer type. So
stop spamming the kernel log whenever this happens. The kernel
will just return -EINVAL to signal this.

Signed-off-by: Hans Verkuil 
Acked-by: Sakari Ailus 
Signed-off-by: Mauro Carvalho Chehab 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

media: v4l2-compat-ioctl32.c: copy clip list in put_v4l2_window32

2018-04-08T09:49:46+00:00

commit a751be5b142ef6bcbbb96d9899516f4d9c8d0ef4 upstream.

put_v4l2_window32() didn't copy back the clip list to userspace.
Drivers can update the clip rectangles, so this should be done.

Signed-off-by: Hans Verkuil 
Acked-by: Sakari Ailus 
Signed-off-by: Mauro Carvalho Chehab 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

media: v4l2-compat-ioctl32: Copy v4l2_window->global_alpha

2018-04-08T09:49:46+00:00

commit 025a26fa14f8fd55d50ab284a30c016a5be953d0 upstream.

Commit b2787845fb91 ("V4L/DVB (5289): Add support for video output
overlays.") added the field global_alpha to struct v4l2_window but did
not update the compat layer accordingly. This change adds global_alpha
to struct v4l2_window32 and copies the value for global_alpha back and
forth.

Signed-off-by: Daniel Mentz 
Signed-off-by: Hans Verkuil 
Signed-off-by: Mauro Carvalho Chehab 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman