nfp: bpf: reject program on instructions unknown to the JIT compiler

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.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

3 files changed, 12 insertions, 0 deletions

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 b80e75a8ecda..c476bca15ba4 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");