netdev - Re: [PATCH bpf-next v4 0/4] Use correct destructor kfunc types

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: <CAADnVQJVEEcRy9C99sPuo-LYPf_7Tu3AwF6gYx5nrk700Y1Eww@mail.gmail.com>
Date: Mon, 5 Jan 2026 08:16:05 -0800
From: Alexei Starovoitov <alexei.starovoitov@...il.com>
To: Viktor Malik <vmalik@...hat.com>
Cc: bpf <bpf@...r.kernel.org>, Vadim Fedorenko <vadim.fedorenko@...ux.dev>, 
	Alexei Starovoitov <ast@...nel.org>, Daniel Borkmann <daniel@...earbox.net>, 
	Andrii Nakryiko <andrii@...nel.org>, Martin KaFai Lau <martin.lau@...ux.dev>, 
	Eduard Zingerman <eddyz87@...il.com>, Song Liu <song@...nel.org>, 
	Yonghong Song <yonghong.song@...ux.dev>, John Fastabend <john.fastabend@...il.com>, 
	KP Singh <kpsingh@...nel.org>, Stanislav Fomichev <sdf@...ichev.me>, Hao Luo <haoluo@...gle.com>, 
	Jiri Olsa <jolsa@...nel.org>, Jamal Hadi Salim <jhs@...atatu.com>, 
	Cong Wang <xiyou.wangcong@...il.com>, Jiri Pirko <jiri@...nulli.us>, 
	Network Development <netdev@...r.kernel.org>, LKML <linux-kernel@...r.kernel.org>, 
	Sami Tolvanen <samitolvanen@...gle.com>
Subject: Re: [PATCH bpf-next v4 0/4] Use correct destructor kfunc types

On Mon, Jan 5, 2026 at 5:56 AM Viktor Malik <vmalik@...hat.com> wrote:
>
> On 11/26/25 23:17, Sami Tolvanen wrote:
> > Hi folks,
> >
> > While running BPF self-tests with CONFIG_CFI (Control Flow
> > Integrity) enabled, I ran into a couple of failures in
> > bpf_obj_free_fields() caused by type mismatches between the
> > btf_dtor_kfunc_t function pointer type and the registered
> > destructor functions.
> >
> > It looks like we can't change the argument type for these
> > functions to match btf_dtor_kfunc_t because the verifier doesn't
> > like void pointer arguments for functions used in BPF programs,
> > so this series fixes the issue by adding stubs with correct types
> > to use as destructors for each instance of this I found in the
> > kernel tree.
> >
> > The last patch changes btf_check_dtor_kfuncs() to enforce the
> > function type when CFI is enabled, so we don't end up registering
> > destructors that panic the kernel.
>
> Hi,
>
> this seems to have slipped through the cracks so I'm bumping the thread.
> It would be nice if we could merge this.

It did. Please rebase, resend.