On Tue, Oct 10, 2023 at 6:17 PM Paul Moore <paul@xxxxxxxxxxxxxx> wrote: > > On Sep 27, 2023 Andrii Nakryiko <andrii@xxxxxxxxxx> wrote: > > > > Add basic support of BPF token to BPF_PROG_LOAD. Wire through a set of > > allowed BPF program types and attach types, derived from BPF FS at BPF > > token creation time. Then make sure we perform bpf_token_capable() > > checks everywhere where it's relevant. > > > > Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx> > > --- > > include/linux/bpf.h | 6 ++ > > include/uapi/linux/bpf.h | 2 + > > kernel/bpf/core.c | 1 + > > kernel/bpf/inode.c | 6 +- > > kernel/bpf/syscall.c | 87 ++++++++++++++----- > > kernel/bpf/token.c | 25 ++++++ > > tools/include/uapi/linux/bpf.h | 2 + > > .../selftests/bpf/prog_tests/libbpf_probes.c | 2 + > > .../selftests/bpf/prog_tests/libbpf_str.c | 3 + > > 9 files changed, 108 insertions(+), 26 deletions(-) > > ... > > > diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c > > index 5c5c2b6648b2..d0b219f09bcc 100644 > > --- a/kernel/bpf/syscall.c > > +++ b/kernel/bpf/syscall.c > > @@ -2685,6 +2718,10 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size) > > prog->aux->sleepable = attr->prog_flags & BPF_F_SLEEPABLE; > > prog->aux->xdp_has_frags = attr->prog_flags & BPF_F_XDP_HAS_FRAGS; > > > > + /* move token into prog->aux, reuse taken refcnt */ > > + prog->aux->token = token; > > + token = NULL; > > + > > err = security_bpf_prog_alloc(prog->aux); > > if (err) > > goto free_prog; > > As we discussed in the earlier thread, let's tweak/rename/move the > security_bpf_prog_alloc() call down to just before the bpf_check() call > so it looks something like this: > > err = security_bpf_prog_load(prog, &attr, token); > if (err) > goto proper_jump_label; > > err = bpf_check(...); > > With the idea being that LSMs which implement the token hooks would > skip any BPF_PROG_LOAD access controls in security_bpf() and instead > implement them in security_bpf_prog_load(). > > We should also do something similar for map_create() and > security_bpf_map_alloc() in patch 4/13. Sounds good, will do! > > -- > paul-moore.com
