Messages in this thread | | | Date | Thu, 5 Apr 2018 09:48:20 +0800 | From | joeyli <> | Subject | Re: An actual suggestion (Re: [GIT PULL] Kernel lockdown for secure boot) |
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On Wed, Apr 04, 2018 at 11:19:27PM +0100, David Howells wrote: > Jann Horn <jannh@google.com> wrote: > > > > Uh, no. bpf, for example, can be used to modify kernel memory. > > > > I'm pretty sure bpf isn't supposed to be able to modify arbitrary > > kernel memory. AFAIU if you can use BPF to write to arbitrary kernel > > memory, that's a bug; with CAP_SYS_ADMIN, you can read from userspace, > > write to userspace, and read from kernelspace, but you shouldn't be > > able to write to kernelspace. > > Ah - you may be right. I seem to have misremembered what Joey Lee wrote in > his patch description. >
Sorry for it's my fault to misunderstood the behavoir of bpf with CAP_SYS_ADMIN.
Joey Lee
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