On Tue, Mar 7, 2017 at 3:26 PM, Eric Dumazet <eric.duma...@gmail.com> wrote: > On Tue, 2017-03-07 at 14:58 +0100, Alexander Potapenko wrote: >> KMSAN (KernelMemorySanitizer, a new error detection tool) reports use >> of uninitialized memory in put_cmsg()): > > I would prefer that you do not put the stack trace in the changelog, > same for the reproducer since this has little value in understanding the > impact. Understood. Should be ok to put the report/reproducer below the triple dash, right?
> It looks like a false positive, but you do not say. Ah, now I see. Irrespective of the value of (MSG_CMSG_COMPAT & msg->msg_flags) the code will return 0 either directly from put_cmsg(), or from put_cmsg_compat(). I wouldn't call this a false positive, as KMSAN can't possibly know that both branches taken depending on the uninitialized condition are safe. But I can imagine this to be less of an problem to the code owners who do know that :) > recvmsg() does not care about msg.msg_flags, only KMSAN. > > (The important part is that msg.msg_control and msg.msg_controllen are > 0) > > Fine to avoid the false positive, but better be explicit in the > changelog and says there is no visible effect for this bug. Ok, I'll change the description. > If there is a visible effect, please state so instead of technical > details. > > We try to reduce S/N in the changelogs ;) > > Thanks a lot ! > > -- Alexander Potapenko Software Engineer Google Germany GmbH Erika-Mann-Straße, 33 80636 München Geschäftsführer: Matthew Scott Sucherman, Paul Terence Manicle Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg
