Re: [PATCH v2 3/5] ebpf: add a way to dump an eBPF program

[Tycho Andersen <tycho.andersen@canonical.com>]

On Thu, Sep 10, 2015 at 07:29:42PM -0700, Alexei Starovoitov wrote:
> On Thu, Sep 10, 2015 at 06:21:00PM -0600, Tycho Andersen wrote:
> > +static int bpf_prog_dump(union bpf_attr *attr, union bpf_attr __user *uattr)
> > +{
> > +	int ufd = attr->prog_fd;
> > +	struct fd f = fdget(ufd);
> > +	struct bpf_prog *prog;
> > +	int ret = -EINVAL;
> > +
> > +	prog = get_prog(f);
> > +	if (IS_ERR(prog))
> > +		return PTR_ERR(prog);
> > +
> > +	/* For now, let's refuse to dump anything that isn't a seccomp program.
> > +	 * Other program types have support for maps, which our current dump
> > +	 * code doesn't support.
> > +	 */
> > +	if (prog->type != BPF_PROG_TYPE_SECCOMP)
> > +		goto out;
> > +
> > +	ret = -EFAULT;
> > +	if (put_user(prog->len, &uattr->dump_insn_cnt))
> > +		goto out;
> > +
> > +	if (put_user((u8) prog->gpl_compatible, &uattr->gpl_compatible))
> > +		goto out;
> > +
> > +	if (attr->dump_insns) {
> > +		u32 len = prog->len * sizeof(struct bpf_insn);
> > +
> > +		if (copy_to_user(u64_to_ptr(attr->dump_insns),
> > +				 prog->insns, len) != 0)
> > +			goto out;
> > +	}
> > +
> > +	ret = 0;
> > +out:
> > +	return ret;
> 
> fdput() is missing in all error paths.

So it is, thanks!

Tycho