Messages in this thread | | | Date | Wed, 09 Sep 2015 18:13:57 +0200 | From | Daniel Borkmann <> | Subject | Re: [PATCH 1/6] ebpf: add a seccomp program type |
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On 09/04/2015 11:50 PM, Andy Lutomirski wrote: > On Fri, Sep 4, 2015 at 9:04 AM, Tycho Andersen [...] >> +static const struct bpf_func_proto * >> +seccomp_func_proto(enum bpf_func_id func_id) >> +{ >> + /* Right now seccomp eBPF loading doesn't support maps; seccomp filters >> + * are considered to be read-only after they're installed, so map fds >> + * probably need to be invalidated when a seccomp filter with maps is >> + * installed. >> + * >> + * The rest of these might be reasonable to call from seccomp, so we >> + * export them. >> + */ >> + switch (func_id) { >> + case BPF_FUNC_ktime_get_ns: >> + return &bpf_ktime_get_ns_proto; >> + case BPF_FUNC_trace_printk: >> + return bpf_get_trace_printk_proto(); >> + case BPF_FUNC_get_prandom_u32: >> + return &bpf_get_prandom_u32_proto; > > I don't think we should expose prandom to unprivileged userspace. > This may be an attack vector.
Agreed, it should not be exposed for unpriv'ed users.
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