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

Andy Lutomirski luto at kernel.org
Mon Aug 5 21:29:05 UTC 2019


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 at kernel.org>
---
 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



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