From: Menglong Dong <menglong.dong@linux.dev>
To: Feng Yang <yangfeng59949@163.com>
Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org,
martin.lau@linux.dev, eddyz87@gmail.com, memxor@gmail.com,
song@kernel.org, yonghong.song@linux.dev, jolsa@kernel.org,
john.fastabend@gmail.com, kpsingh@kernel.org,
mattbobrowski@google.com, jiayuan.chen@linux.dev,
leon.hwang@linux.dev, bpf@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
Feng Yang <yangfeng@kylinos.cn>
Subject: Re: [PATCH v3 bpf-next 1/2] bpf: Fix Null-Pointer Dereference in kernel_clone() via BPF fmod_ret on security_task_alloc
Date: Sun, 12 Apr 2026 11:39:53 +0800 [thread overview]
Message-ID: <4726660.LvFx2qVVIh@7950hx> (raw)
In-Reply-To: <20260411163556.8567-2-yangfeng59949@163.com>
On 2026/4/12 00:35, Feng Yang wrote:
> From: Feng Yang <yangfeng@kylinos.cn>
>
[...]
>
> static bool return_retval_range(struct bpf_verifier_env *env, struct bpf_retval_range *range)
> {
> @@ -18416,8 +18522,13 @@ static bool return_retval_range(struct bpf_verifier_env *env, struct bpf_retval_
> *range = retval_range(0, 0);
> break;
> case BPF_TRACE_RAW_TP:
> - case BPF_MODIFY_RETURN:
> return false;
> + case BPF_MODIFY_RETURN:
> + if (!bpf_security_get_retval_range(env->prog, range))
> + break;
> + if (modify_return_get_retval_range(env->prog, range))
> + return false;
> + break;
return false by default, as what we did in the previous logic?
+ case BPF_MODIFY_RETURN:
+ if (!bpf_security_get_retval_range(env->prog, range))
+ break;
+ if (!modify_return_get_retval_range(env->prog, range))
+ break;
+ return false;
> case BPF_TRACE_ITER:
> default:
> break;
> @@ -25460,7 +25571,6 @@ static int check_struct_ops_btf_id(struct bpf_verifier_env *env)
> return bpf_prog_ctx_arg_info_init(prog, st_ops_desc->arg_info[member_idx].info,
> st_ops_desc->arg_info[member_idx].cnt);
> }
> -#define SECURITY_PREFIX "security_"
>
> #ifdef CONFIG_FUNCTION_ERROR_INJECTION
>
>
next prev parent reply other threads:[~2026-04-12 3:40 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-11 16:35 [PATCH v3 bpf-next 0/2] bpf: Fix Null-Pointer Dereference in kernel_clone() via BPF fmod_ret on security_task_alloc Feng Yang
2026-04-11 16:35 ` [PATCH v3 bpf-next 1/2] " Feng Yang
2026-04-11 17:32 ` Alexei Starovoitov
2026-04-12 2:40 ` Feng Yang
2026-04-12 3:39 ` Menglong Dong [this message]
2026-04-11 16:35 ` [PATCH v3 bpf-next 2/2] selftests/bpf: Add selftests for verifying return values of fmod_ret Feng Yang
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