linux-kernel - Re: [PATCH bpf-next v3 1/2] bpf: Make the pointer returned by iter next method valid

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAADnVQ+P=j0MTkyDD0vYcaqU-qqdE_+mi+gDaqDsLqTXWNPHwA@mail.gmail.com>
Date: Thu, 29 Aug 2024 11:37:51 -0700
From: Alexei Starovoitov <alexei.starovoitov@...il.com>
To: Juntong Deng <juntong.deng@...look.com>
Cc: Alexei Starovoitov <ast@...nel.org>, Daniel Borkmann <daniel@...earbox.net>, 
	John Fastabend <john.fastabend@...il.com>, Andrii Nakryiko <andrii@...nel.org>, 
	Martin KaFai Lau <martin.lau@...ux.dev>, Eddy Z <eddyz87@...il.com>, Song Liu <song@...nel.org>, 
	Yonghong Song <yonghong.song@...ux.dev>, KP Singh <kpsingh@...nel.org>, 
	Stanislav Fomichev <sdf@...ichev.me>, Hao Luo <haoluo@...gle.com>, Jiri Olsa <jolsa@...nel.org>, 
	Kumar Kartikeya Dwivedi <memxor@...il.com>, snorcht@...il.com, bpf <bpf@...r.kernel.org>, 
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH bpf-next v3 1/2] bpf: Make the pointer returned by iter
 next method valid

On Thu, Aug 29, 2024 at 3:45 AM Juntong Deng <juntong.deng@...look.com> wrote:
>
>                 if (prev_st)
> @@ -12860,6 +12867,16 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
>                         /* For mark_ptr_or_null_reg, see 93c230e3f5bd6 */
>                         regs[BPF_REG_0].id = ++env->id_gen;
>                 }
> +
> +               if (is_iter_next_kfunc(&meta) && base_type(regs[BPF_REG_0].type) != PTR_TO_MEM) {

The != PTR_TO_MEM part is a bit ugly.

Why not do it in {} scope right above?
Just move it up by a few lines?
Right after regs[BPF_REG_0].type = PTR_TO_BTF_ID;