Messages in this thread | | | From | Alexei Starovoitov <> | Date | Thu, 22 Dec 2016 11:34:36 -0800 | Subject | Re: BPF hash algo (Re: [kernel-hardening] Re: [PATCH v7 3/6] random: use SipHash in place of MD5) |
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On Thu, Dec 22, 2016 at 9:25 AM, Andy Lutomirski <luto@amacapital.net> wrote: > On Thu, Dec 22, 2016 at 8:59 AM, Hannes Frederic Sowa > <hannes@stressinduktion.org> wrote: >> On Thu, 2016-12-22 at 08:07 -0800, Andy Lutomirski wrote: >> >> We don't prevent ebpf programs being loaded based on the digest but >> just to uniquely identify loaded programs from user space and match up >> with their source. > > The commit log talks about using the hash to see if the program has > already been compiled and JITted. If that's done, then a collision > will directly cause the kernel to malfunction.
Andy, please read the code. we could have used jhash there just as well. Collisions are fine.
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