On Mon, Nov 14, 2016 at 03:45:36PM -0500, Josef Bacik wrote: > I made some invalid assumptions with BPF_AND and BPF_MOD that could result in > invalid accesses to bpf map entries. Fix this up by doing a few things > > 1) Kill BPF_MOD support. This doesn't actually get used by the compiler in > real > life and just adds extra complexity. > > 2) Fix the logic for BPF_AND, don't allow AND of negative numbers and set the > minimum value to 0 for positive AND's. > > 3) Don't do operations on the ranges if they are set to the limits, as they > are > by definition undefined, and allowing arithmetic operations on those values > could make them appear valid when they really aren't. > > This fixes the testcase provided by Jann as well as a few other theoretical > problems. > > Reported-by: Jann Horn <ja...@google.com> > Signed-off-by: Josef Bacik <jba...@fb.com>
lgtm. Acked-by: Alexei Starovoitov <a...@kernel.org> Jann, could you please double check the logic. Thanks!
