| Message ID | 1441382664-17437-7-git-send-email-tycho.andersen@canonical.com |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 039d866..2fff8cd 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1080,7 +1080,12 @@ static int check_cond_jmp_op(struct verifier_env *env, if (err) return err; } else { - if (insn->src_reg != BPF_REG_0) { + switch (insn->src_reg) { + case BPF_REG_0: + /* the classic converter generates BPF_JMP with src_reg of X */ + case BPF_REG_X: + break; + default: verbose("BPF_JMP uses reserved fields\n"); return -EINVAL; }
The classic converter generates conditional jumps with: if (BPF_SRC(fp->code) == BPF_K && (int) fp->k < 0) { ... } else { insn->dst_reg = BPF_REG_A; insn->src_reg = BPF_REG_X; insn->imm = fp->k; bpf_src = BPF_SRC(fp->code); } but here, we enforce that the src_reg == BPF_REG_0. We should also allow BPF_REG_X since that's what the converter generates; this enables us to load eBPF programs that were generated by the converter. Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com> CC: Kees Cook <keescook@chromium.org> CC: Will Drewry <wad@chromium.org> CC: Oleg Nesterov <oleg@redhat.com> CC: Andy Lutomirski <luto@amacapital.net> CC: Pavel Emelyanov <xemul@parallels.com> CC: Serge E. Hallyn <serge.hallyn@ubuntu.com> CC: Alexei Starovoitov <ast@kernel.org> CC: Daniel Borkmann <daniel@iogearbox.net> --- kernel/bpf/verifier.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)