From: "Kumar Kartikeya Dwivedi" <memxor@gmail.com>
To: "Amery Hung" <ameryhung@gmail.com>, <bpf@vger.kernel.org>
Cc: <alexei.starovoitov@gmail.com>, <andrii@kernel.org>,
<daniel@iogearbox.net>, <eddyz87@gmail.com>, <memxor@gmail.com>,
<kernel-team@meta.com>
Subject: Re: [PATCH bpf-next v1 2/2] bpf: Zero kfunc arg meta before error paths can read it
Date: Wed, 15 Jul 2026 20:09:56 +0200 [thread overview]
Message-ID: <DJZCHNTTXDXY.2SETI3I98235S@gmail.com> (raw)
In-Reply-To: <20260715172127.2416388-3-ameryhung@gmail.com>
On Wed Jul 15, 2026 at 7:21 PM CEST, Amery Hung wrote:
> check_kfunc_call() reads meta.func_name when bpf_fetch_kfunc_arg_meta()
> returns -EACCES, but that error can come from fetch_kfunc_meta() (e.g.
> fd_array_get_btf() rejecting BTF binding for a signed program) before
> meta is memset(), leaving it uninitialized and risking a garbage deref
> in verbose().
>
> Move the memset() to the start of bpf_fetch_kfunc_arg_meta() so meta is
> zeroed on every error return. The intended "not allowed" -EACCES path
> still sets func_name first, so its message is unchanged.
>
> Signed-off-by: Amery Hung <ameryhung@gmail.com>
> ---
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
prev parent reply other threads:[~2026-07-15 18:09 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-15 17:21 [PATCH bpf-next v1 0/2] Fix leftover issues of the unify bpf_call_arg_meta patchset Amery Hung
2026-07-15 17:21 ` [PATCH bpf-next v1 1/2] bpf: Disable raw mdoe for bloom filter map_peek Amery Hung
2026-07-15 17:38 ` sashiko-bot
2026-07-15 18:07 ` Kumar Kartikeya Dwivedi
2026-07-15 18:06 ` bot+bpf-ci
2026-07-15 18:18 ` Kumar Kartikeya Dwivedi
2026-07-15 17:21 ` [PATCH bpf-next v1 2/2] bpf: Zero kfunc arg meta before error paths can read it Amery Hung
2026-07-15 17:38 ` sashiko-bot
2026-07-15 18:11 ` Kumar Kartikeya Dwivedi
2026-07-15 18:06 ` bot+bpf-ci
2026-07-15 18:09 ` Kumar Kartikeya Dwivedi [this message]
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