From: Alexander Potapenko <gli...@google.com> Date: Tue, 25 Apr 2017 18:27:04 +0200
> On Tue, Apr 25, 2017 at 5:44 PM, David Miller <da...@davemloft.net> wrote: >> From: Alexander Potapenko <gli...@google.com> >> Date: Mon, 24 Apr 2017 14:59:14 +0200 >> >>> In the case getsockopt() is called with PACKET_HDRLEN and optlen < 4 >>> |val| remains uninitialized and the syscall may behave differently >>> depending on its value. This doesn't have security consequences (as the >>> uninit bytes aren't copied back), but it's still cleaner to initialize >>> |val| and ensure optlen is not less than sizeof(int). >>> >>> This bug has been detected with KMSAN. >>> >>> Signed-off-by: Alexander Potapenko <gli...@google.com> >>> --- >>> v2: - if len < sizeof(int), make it 0 >> >> No, you should signal an error if the len is too small. > According to manpages, only setsockopt() may return EINVAL. > Is it ok to change the behavior of getsockopt() to return EINVAL in > this case? (I.e. won't we break existing users that don't expect it?) They are currently getting corrupt data depending upon the endianness, so -EINVAL is a serious improvement.
