From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from 66-220-144-179.mail-mxout.facebook.com (66-220-144-179.mail-mxout.facebook.com [66.220.144.179]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D2A889475 for ; Sun, 12 Apr 2026 05:00:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=66.220.144.179 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775970023; cv=none; b=IqBvaJS5BTshqTbmGl5f9lyZyHBnHAS7PJVwJz4nMnBXq8i1IrEEBPFBr35bXF2O+daF+wrFRkaAs08zN5vvWauh760mLOYeS4F36OUZEr7FFnt68tUyPB8dv9+YlczwZAUPyWOE4Hpia52dOTyq6j9pVU0hdf9Oo4ePzt9FJh4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775970023; c=relaxed/simple; bh=/VANlIrMcOdGBRhisNYMQo2n8w2kkMcYYCy39542QSA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=UINNCQxgELDx18HxaslTWHLvbPzLF1gdX8aieDK05ApvAY7Y0HWzHukXNPhVNbhJMdk5Bnoxss4YazCw3VfCXR1Gm1WgVape1+/vsbERbUw5chqs7IolBlE9Ty77+yn7Q9igyLs0Z/HrVbbFqj6sHRGMnunFdqMz5myrz3ij09s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.dev; spf=fail smtp.mailfrom=linux.dev; arc=none smtp.client-ip=66.220.144.179 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=linux.dev Received: by devvm16039.vll0.facebook.com (Postfix, from userid 128203) id B9DF53B021C03; Sat, 11 Apr 2026 22:00:10 -0700 (PDT) From: Yonghong Song To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , "Jose E . Marchesi" , kernel-team@fb.com, Martin KaFai Lau Subject: [PATCH bpf-next v4 12/18] bpf: Reject stack arguments if tail call reachable Date: Sat, 11 Apr 2026 22:00:10 -0700 Message-ID: <20260412050010.266625-1-yonghong.song@linux.dev> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260412045826.254200-1-yonghong.song@linux.dev> References: <20260412045826.254200-1-yonghong.song@linux.dev> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Tailcalls are been deprecated. So reject stack arguments if tail call is in the way. Signed-off-by: Yonghong Song --- kernel/bpf/verifier.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 20fb53ead728..45987041bb2a 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -7175,6 +7175,11 @@ static int check_max_stack_depth_subprog(struct bp= f_verifier_env *env, int idx, verbose(env, "cannot tail call within exception cb\n"); return -EINVAL; } + if (subprog[tmp].incoming_stack_arg_depth || + subprog[tmp].outgoing_stack_arg_depth) { + verbose(env, "tail_calls are not allowed in programs with stack args= \n"); + return -EINVAL; + } subprog[tmp].tail_call_reachable =3D true; } if (subprog[0].tail_call_reachable) --=20 2.52.0