From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3FB4C3BCD26 for ; Mon, 17 Aug 2026 21:11:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787001087; cv=none; b=dQAIFgO0uDzM8Ld0wBj684Hi6C3hhbSEMytPgXOEss/bH2jomUv4YQ+S47uJgEy+Ntf363RAhbZoQlrlA1zOQWat+GtTV4qr82t0fCkSqEHpFh1hD6Q/327Wr8CE03ydrlDwd0QIcitn9ldMUCgQb8iFFdEnev2fLyaqyRTBrBY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787001087; c=relaxed/simple; bh=afLRo5nxPZ5GOlB+xhsiXt6r+d8uK/V6XJLuSFQ/M3E=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=e3g5Hh+ru9pI8yogN/VMQLGoBk/qMXRbe8jLvdlyoN3IrEgLR84XAnagKjy7tqaN+EKqiKEQQVC3vxgDpvJ3g2t204MVrjzBHb+1cu1XDxc9T1QFMV6injEfPl4MKx1vZcq5diBlknxMi6eGmXyER0VT/CkQgdPzu5f5ORlWirU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=SUlq3Bhq; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="SUlq3Bhq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A67591F000E9; Mon, 17 Aug 2026 21:11:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787001085; bh=uddfXaMkmWwwsZVsBxdv4cLASBaDxSB0GM/7RIM6n8E=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=SUlq3BhqdDDOHFH1rsat4dfe73MblEOjL5Kq9ZJbdfbyF5ElugtjnDSB3bCR8YTms noXxm/a4VpHTBN3wU1AamUN2GwzKkSNKhvbX0kMWJiKEu3LYDHUrP+LkY9AaJ42weN /tiqUzyp5rDuhK+k4EdRnn+rKIudBF5HfO9sfqzGaKmfMrKkWd+NMlcLyFi4YlgGzs SWeOcaw3hKUVb4EQL2X3+WzjmwOzRNZqOCzQhskHi1kgx8USRGtD6sMeLOH5K4QVcI mN1NCbjCrmm5w9VVJlU2nAhTn3OSJYqMRMMVa7wLjfvgRjuD9HVIj+28yyydH7y0hr 8TA0lTf/wjdLA== From: sashiko-bot@kernel.org Subject: Re: [PATCH v2 1/2] bpf: reject stack-argument callback subprograms Reply-To: sashiko-reviews@lists.linux.dev To: =?utf-8?b?SsOpcsOpbXkgSmVhbg==?= Cc: bpf@vger.kernel.org In-Reply-To: <20260817204812.1637171-2-Jeremy.Jean@oss.cyber.gouv.fr> References: <20260817204812.1637171-1-Jeremy.Jean@oss.cyber.gouv.fr> <20260817204812.1637171-2-Jeremy.Jean@oss.cyber.gouv.fr> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Mon, 17 Aug 2026 21:11:25 +0000 Message-Id: <20260817211125.A67591F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Thank you for your contribution! Sashiko AI review found 1 potential issue(= s) to consider: - [Medium] The patch silently rejects callback subprograms with stack argum= ents by returning `-EINVAL` without emitting a verifier log message. -- --- Patch [1]: [PATCH v2 1/2] bpf: reject stack-argument callback subprogra= ms --- commit 0a06c150da6a5163953fb53d000c974d1e9a97dc Author: J=C3=A9r=C3=A9my Jean bpf: reject stack-argument callback subprograms This commit rejects callback subprograms that declare incoming stack argume= nts when processing callback calls. It prevents out-of-bounds reads in callbacks that attempt to read arguments from the helper's native frame instead of the synthetic verifier values. > diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c > index fdc5fbb1f78ca..5fcefc0eaba00 100644 > --- a/kernel/bpf/verifier.c > +++ b/kernel/bpf/verifier.c > @@ -9285,6 +9285,8 @@ static int push_callback_call(struct bpf_verifier_e= nv *env, struct bpf_insn *ins > err =3D btf_check_subprog_call(env, subprog, caller->regs); > if (err =3D=3D -EFAULT) > return err; > + if (bpf_in_stack_arg_cnt(&env->subprog_info[subprog])) > + return -EINVAL; [Severity: Medium] Does this silently reject the callback subprogram without providing a verif= ier log message? Returning -EINVAL without using verbose() leaves the user with an opaque error when a BPF program uses a callback subprogram with stack arguments. Would it be helpful to add a verbose() log here to explain the l= oad failure to BPF developers? > =20 > /* set_callee_state is used for direct subprog calls, but we are > * interested in validating only BPF helpers that can call subprogs as --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260817204812.1637= 171-1-Jeremy.Jean@oss.cyber.gouv.fr?part=3D1