1. 29 7月, 2013 1 次提交
  2. 23 7月, 2013 1 次提交
  3. 22 7月, 2013 1 次提交
    • J
      HID: fix data access in implement() · 27ce4050
      Jiri Kosina 提交于
      implement() is setting bytes in LE data stream. In case the data is not
      aligned to 64bits, it reads past the allocated buffer. It doesn't really
      change any value there (it's properly bitmasked), but in case that this
      read past the boundary hits a page boundary, pagefault happens when
      accessing 64bits of 'x' in implement(), and kernel oopses.
      
      This happens much more often when numbered reports are in use, as the
      initial 8bit skip in the buffer makes the whole process work on values
      which are not aligned to 64bits.
      
      This problem dates back to attempts in 2005 and 2006 to make implement()
      and extract() as generic as possible, and even back then the problem
      was realized by Adam Kroperlin, but falsely assumed to be impossible
      to cause any harm:
      
        http://www.mail-archive.com/linux-usb-devel@lists.sourceforge.net/msg47690.html
      
      I have made several attempts at fixing it "on the spot" directly in
      implement(), but the results were horrible; the special casing for processing
      last 64bit chunk and switching to different math makes it unreadable mess.
      
      I therefore took a path to allocate a few bytes more which will never make
      it into final report, but are there as a cushion for all the 64bit math
      operations happening in implement() and extract().
      
      All callers of hid_output_report() are converted at the same time to allocate
      the buffer by newly introduced hid_alloc_report_buf() helper.
      
      Bruno noticed that the whole raw_size test can be dropped as well, as
      hid_alloc_report_buf() makes sure that the buffer is always of a proper
      size.
      Reviewed-by: NBenjamin Tissoires <benjamin.tissoires@redhat.com>
      Acked-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
      Signed-off-by: NJiri Kosina <jkosina@suse.cz>
      27ce4050
  4. 15 7月, 2013 1 次提交
  5. 13 7月, 2013 1 次提交
  6. 04 7月, 2013 35 次提交