From: Feng Yang <yangfeng59949@163.com>
To: olsajiri@gmail.com
Cc: andrii@kernel.org, ast@kernel.org, bpf@vger.kernel.org,
daniel@iogearbox.net, eddyz87@gmail.com,
john.fastabend@gmail.com, kpsingh@kernel.org,
linux-kernel@vger.kernel.org, martin.lau@linux.dev,
mattbobrowski@google.com, memxor@gmail.com, song@kernel.org,
yangfeng59949@163.com, yonghong.song@linux.dev
Subject: Re: [PATCH bpf] bpf: Fix Null-Pointer Dereference in kernel_clone() via BPF fmod_ret on security_task_alloc
Date: Thu, 9 Apr 2026 18:24:18 +0800 [thread overview]
Message-ID: <20260409102418.258397-1-yangfeng59949@163.com> (raw)
In-Reply-To: <adZBzjB8bcX344LY@krava>
On Wed, 8 Apr 2026 13:53:50 +0200 Jiri Olsa wrote:
[...]
> > +void bpf_security_get_retval_range(const struct bpf_prog *prog,
> > + struct bpf_retval_range *retval_range)
> > +{
> > + if (btf_id_set_contains(&bool_security_hooks, prog->aux->attach_btf_id)) {
> > + retval_range->minval = 0;
> > + retval_range->maxval = 1;
> > + } else {
> > + retval_range->minval = -MAX_ERRNO;
> > + retval_range->maxval = 0;
> > + }
> > +}
>
> ai has a point that fmod_ret can attach to other than security functions
>
> https://sashiko.dev/#/patchset/20260408094816.228322-1-yangfeng59949%40163.com
>
> most of them seem to return errno (ERRNO), but there's also few with
> 'TRUE' and one with 'NULL' .. we could check if the function is on
> the injection list and check the return value accordingly?
>
> jirka
Oh right, I missed that. I'm also setting the correct return values for the error injection cases and will submit after testing.
next prev parent reply other threads:[~2026-04-09 10:25 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-08 9:48 [PATCH bpf] bpf: Fix Null-Pointer Dereference in kernel_clone() via BPF fmod_ret on security_task_alloc Feng Yang
2026-04-08 11:53 ` Jiri Olsa
2026-04-09 10:24 ` Feng Yang [this message]
2026-04-08 12:16 ` Jiayuan Chen
2026-04-09 10:25 ` Feng Yang
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