Messages in this thread | | | Date | Mon, 25 Mar 2019 16:59:44 -0700 | From | Stephen Hemminger <> | Subject | Re: [PATCH 23/27] bpf: Restrict kernel image access functions when the kernel is locked down |
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On Mon, 25 Mar 2019 16:42:21 -0700 Stephen Hemminger <stephen@networkplumber.org> wrote:
> On Mon, 25 Mar 2019 15:09:50 -0700 > Matthew Garrett <matthewgarrett@google.com> wrote: > > > From: David Howells <dhowells@redhat.com> > > > > There are some bpf functions can be used to read kernel memory: > > bpf_probe_read, bpf_probe_write_user and bpf_trace_printk. These allow > > private keys in kernel memory (e.g. the hibernation image signing key) to > > be read by an eBPF program and kernel memory to be altered without > > restriction. > > > > Completely prohibit the use of BPF when the kernel is locked down. > > > > Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> > > Signed-off-by: David Howells <dhowells@redhat.com> > > cc: netdev@vger.kernel.org > > cc: Chun-Yi Lee <jlee@suse.com> > > cc: Alexei Starovoitov <alexei.starovoitov@gmail.com> > > Cc: Daniel Borkmann <daniel@iogearbox.net> > > Signed-off-by: Matthew Garrett <matthewgarrett@google.com> > > Wouldn't this mean that Seccomp won't work in locked down mode?
Never mind. This is about bpf system call, not locking out all bpf in general.
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