[WIP 4/4] bpf: Allow creating all program types without privilege

From: Andy Lutomirski
Date: Mon Aug 05 2019 - 17:29:32 EST


This doesn't let you *run* the programs except in test mode, so it should
be safe. Famous last words.

This assumes that the check-privilege-to-call-privileged-functions
patch actually catches all the cases and that there's nothing else
that should need privilege lurking in the type-specific verifiers.

Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
---
kernel/bpf/syscall.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 23f8f89d2a86..730afa2be786 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1649,8 +1649,7 @@ static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr)
attr->insn_cnt > (capable(CAP_SYS_ADMIN) ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS))
return -E2BIG;
if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
- type != BPF_PROG_TYPE_CGROUP_SKB &&
- !capable(CAP_SYS_ADMIN))
+ type != BPF_PROG_TYPE_CGROUP_SKB)
return -EPERM;

bpf_prog_load_fixup_attach_type(attr);
--
2.21.0