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

[Alexei Starovoitov]

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.

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