Re: [char-misc v4.4.y 2/2] mei: bus: type promotion bug in mei_nfc_if_version()

[Greg Kroah-Hartman]

On Tue, Sep 04, 2018 at 01:43:04AM +0300, Tomas Winkler wrote:
> From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> 
> commit b40b3e9358fbafff6a4ba0f4b9658f6617146f9c upstream
> 
> We accidentally removed the check for negative returns
> without considering the issue of type promotion.
> The "if_version_length" variable is type size_t so if __mei_cl_recv()
> returns a negative then "bytes_recv" is type promoted
> to a high positive value and treated as success.
> 
> Cc: <stable@xxxxxxxxxxxxxxx> # 4.4

I also need a version of this patch for 4.18.y, 4.14.y, and 4.9.y before
I will consider adding it to 4.4.y, as we do not want anyone to ever get
a regression moving to a new kernel.

thanks,

greg k-h