<tt>Jim Meyering <jim@meyering.net> wrote on 03/29/2010 01:22:56 PM: > [image removed] </tt> <tt>> > Re: [libvirt] [PATCH] nwfilter_ebiptables_driver.c: avoid NULL dereference</tt> <tt>> > Jim Meyering </tt> <tt>> > to:</tt> <tt>> > Eric Blake</tt> <tt>> > 03/29/2010 01:23 PM</tt> <tt>> > Cc:</tt> <tt>> > Stefan Berger, Libvirt</tt> <tt>> > Eric Blake wrote: > > On 03/29/2010 10:37 AM, Jim Meyering wrote: > >> Another one caught by clang: > >> > >> Note the first test to see if "inst" may be NULL. > >> Then, in the following loop, "inst" is unconditionally > >> dereferenced via "inst[i]". There are other unprotected > >> used of "inst[i]" below, too. > >> > >> Rather than trying to protect all uses, one by one, I chose > >> to return "success" when given an empty list of rules. > > > > ACK that your patch is the minimal fix to avoid a segfault, but we > > should probably get Stefan's input on whether returning success on an > > empty input is the best course of behavior. > > Ok. I've Cc'd him.</tt> <tt>Actually the inst[n] accesses are protected by nInstances having to be > 0 for code to try to read a inst[n]. So it should be fine the way it is. nInstances and inst belong together and nInstances indicates the number of members in that array. No member of inst[] is expected to be NULL.</tt> <tt> Stefan </tt>