• Jonathan Cameron's avatar
    iio:humidity:hts221 Fix alignment and data leak issues · 5c49056a
    Jonathan Cameron authored
    One of a class of bugs pointed out by Lars in a recent review.
    iio_push_to_buffers_with_timestamp assumes the buffer used is aligned
    to the size of the timestamp (8 bytes).  This is not guaranteed in
    this driver which uses an array of smaller elements on the stack.
    As Lars also noted this anti pattern can involve a leak of data to
    userspace and that indeed can happen here.  We close both issues by
    moving to a suitable structure in the iio_priv() data.
    This data is allocated with kzalloc so no data can leak
    apart from previous readings.
    
    Explicit alignment of ts needed to ensure consistent padding
    on all architectures (particularly x86_32 with it's 4 byte alignment
    of s64)
    
    Fixes: e4a70e3e ("iio: humidity: add support to hts221 rh/temp combo device")
    Reported-by: default avatarLars-Peter Clausen <lars@metafoo.de>
    Acked-by: default avatarLorenzo Bianconi <lorenzo@kernel.org>
    Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
    Cc: <Stable@vger.kernel.org>
    5c49056a
hts221_buffer.c 5.27 KB