media: v4l2-core: compat: ignore native command codes
commit 4a873f3f upstream. The do_video_ioctl() compat handler converts the compat command codes into the native ones before processing further, but this causes problems for 32-bit user applications that pass a command code that matches a 64-bit native number, which will then be handled the same way. Specifically, this breaks VIDIOC_DQEVENT_TIME from user space applications with 64-bit time_t, as the structure layout is the same as the native 64-bit layout on many architectures (x86 being the notable exception). Change the handler to use the converted command code only for passing into the native ioctl handler, not for deciding on the conversion, in order to make the compat behavior match the native behavior. Actual support for the 64-bit time_t version of VIDIOC_DQEVENT_TIME and other commands still needs to be added in a separate patch. Cc: stable@vger.kernel.org Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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