Re: [PATCH 2/3] [RFC] seccomp: give BPF x32 bit when restoring x32 filter
On Thursday, July 10, 2014 09:06:02 PM H. Peter Anvin wrote:
Incidentally: do seccomp users know that on an x86-64 system you can
recevie system calls from any of the x86 architectures, regardless of
how the program is invoked? (This is unusual, so normally denying those
"alien" calls is the right thing to do.)
I obviously can't speak for all seccomp users, but libseccomp handles this by
checking the seccomp_data->arch value at the start of the filter and killing
(by default) any non-native architectures. If you want, you can change this
default behavior or add support for other architectures (e.g. create a filter
that allows both x86-64 and x32 but disallows x86, or any combination of the
three for that matter).
--
paul moore
security and virtualization @ redhat