Important regression fix patch

Important regression fix patch

[Mauro Carvalho Chehab]

Hi Greg,

There are two important v4l2-core fixes on the patches merged this week by
Linux.

1) media: v4l2-core: fix size of devnode_nums[] bitarray

This patch correct a regression against Kernel 4.16. It affects notebooks
with advanced Synaptics mice (and similar touch devices). On those devices,
the pad produces an image with is handled via V4L2. Without this patch,
the input driver OOPSes at probing time:

	https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a95845ba184b854106972f5d8f50354c2d272c06

2) v4l2-compat-ioctl32: don't oops on overlay

This patch complements the security fix we've made at the V4L2 core
compat32 logic. It fixes an illegal use of an __user pointer without
first convert into a Kernel pointer with get_user(). It wasn't detect
before, as it uses an obscure streaming mode of V4L2 (overlay mode):

	https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=85ea29f19eab56ec16ec6b92bc67305998706afa

This one should go all the way down to stable Kernels. Here, I was able
to reproduce the bug with both upstream Kernel and Kernel 3.18. The
patch applied without any conflicts on both.

Could you please add both on your next set of -stable releases?

Thanks,
Mauro

Re: Important regression fix patch

[Greg KH]

On Fri, Apr 13, 2018 at 05:48:31AM -0300, Mauro Carvalho Chehab wrote:
> Hi Greg,
> 
> There are two important v4l2-core fixes on the patches merged this week by
> Linux.
> 
> 1) media: v4l2-core: fix size of devnode_nums[] bitarray
> 
> This patch correct a regression against Kernel 4.16. It affects notebooks
> with advanced Synaptics mice (and similar touch devices). On those devices,
> the pad produces an image with is handled via V4L2. Without this patch,
> the input driver OOPSes at probing time:
> 
> 	https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a95845ba184b854106972f5d8f50354c2d272c06
> 
> 2) v4l2-compat-ioctl32: don't oops on overlay
> 
> This patch complements the security fix we've made at the V4L2 core
> compat32 logic. It fixes an illegal use of an __user pointer without
> first convert into a Kernel pointer with get_user(). It wasn't detect
> before, as it uses an obscure streaming mode of V4L2 (overlay mode):
> 
> 	https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=85ea29f19eab56ec16ec6b92bc67305998706afa
> 
> This one should go all the way down to stable Kernels. Here, I was able
> to reproduce the bug with both upstream Kernel and Kernel 3.18. The
> patch applied without any conflicts on both.
> 
> Could you please add both on your next set of -stable releases?

Both now queued up, thanks,

greg k-h