On Fri, 2011-01-28 at 09:00 -0600, Robert Jennings wrote: > Currently zram will do nothing to the page in the bvec when that page > has not been previously written. This allows random data to leak to > user space. That can be seen by doing the following: > > ## Load the module and create a 256Mb zram device called /dev/zram0 > # modprobe zram > # echo $((256*1024*1024)) > /sys/class/block/zram0/disksize > > ## Initialize the device by writing zero to the first block > # dd if=/dev/zero of=/dev/zram0 bs=512 count=1 > > ## Read ~256Mb of memory into a file and hope for something interesting > # dd if=/dev/zram0 of=file > > This patch will treat an unwritten page as a zero-filled page. If a > page is read before a write has occurred the data returned is all 0's. > > Signed-off-by: Robert Jennings <rcj@xxxxxxxxxxxxxxxxxx> Reviewed-by: Pekka Enberg <penberg@xxxxxxxxxx> _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
