[PATCH bpf-next 6/6] nfp: bpf: reject program on instructions unknown to the JIT compiler

[Jakub Kicinski]

From: Quentin Monnet <quentin.mon...@netronome.com>

If an eBPF instruction is unknown to the driver JIT compiler, we can
reject the program at verification time.

Signed-off-by: Quentin Monnet <quentin.mon...@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicin...@netronome.com>
Reviewed-by: Jiong Wang <jiong.w...@netronome.com>
---
 drivers/net/ethernet/netronome/nfp/bpf/jit.c      | 5 +++++
 drivers/net/ethernet/netronome/nfp/bpf/main.h     | 1 +
 drivers/net/ethernet/netronome/nfp/bpf/verifier.c | 6 ++++++
 3 files changed, 12 insertions(+)

diff --git a/drivers/net/ethernet/netronome/nfp/bpf/jit.c 
b/drivers/net/ethernet/netronome/nfp/bpf/jit.c
index cdc949fabe98..56451edf01c2 100644
--- a/drivers/net/ethernet/netronome/nfp/bpf/jit.c
+++ b/drivers/net/ethernet/netronome/nfp/bpf/jit.c
@@ -2907,6 +2907,11 @@ void nfp_bpf_jit_prepare(struct nfp_prog *nfp_prog, 
unsigned int cnt)
        }
 }
 
+bool nfp_bpf_supported_opcode(u8 code)
+{
+       return !!instr_cb[code];
+}
+
 void *nfp_bpf_relo_for_vnic(struct nfp_prog *nfp_prog, struct nfp_bpf_vnic *bv)
 {
        unsigned int i;
diff --git a/drivers/net/ethernet/netronome/nfp/bpf/main.h 
b/drivers/net/ethernet/netronome/nfp/bpf/main.h
index 80855d43b25e..424fe8338105 100644
--- a/drivers/net/ethernet/netronome/nfp/bpf/main.h
+++ b/drivers/net/ethernet/netronome/nfp/bpf/main.h
@@ -324,6 +324,7 @@ struct nfp_bpf_vnic {
 
 void nfp_bpf_jit_prepare(struct nfp_prog *nfp_prog, unsigned int cnt);
 int nfp_bpf_jit(struct nfp_prog *prog);
+bool nfp_bpf_supported_opcode(u8 code);
 
 extern const struct bpf_prog_offload_ops nfp_bpf_analyzer_ops;
 
diff --git a/drivers/net/ethernet/netronome/nfp/bpf/verifier.c 
b/drivers/net/ethernet/netronome/nfp/bpf/verifier.c
index 81dab462456c..479f602887e9 100644
--- a/drivers/net/ethernet/netronome/nfp/bpf/verifier.c
+++ b/drivers/net/ethernet/netronome/nfp/bpf/verifier.c
@@ -290,6 +290,12 @@ nfp_verify_insn(struct bpf_verifier_env *env, int 
insn_idx, int prev_insn_idx)
        meta = nfp_bpf_goto_meta(nfp_prog, meta, insn_idx, env->prog->len);
        nfp_prog->verifier_meta = meta;
 
+       if (!nfp_bpf_supported_opcode(meta->insn.code)) {
+               pr_vlog(env, "instruction %#02x not supported\n",
+                       meta->insn.code);
+               return -EINVAL;
+       }
+
        if (meta->insn.src_reg >= MAX_BPF_REG ||
            meta->insn.dst_reg >= MAX_BPF_REG) {
                pr_vlog(env, "program uses extended registers - jit 
hardening?\n");
-- 
2.15.1