From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3F956C433FE for ; Fri, 25 Feb 2022 15:28:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242067AbiBYP2m (ORCPT ); Fri, 25 Feb 2022 10:28:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55696 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242062AbiBYP2m (ORCPT ); Fri, 25 Feb 2022 10:28:42 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7973120A948 for ; Fri, 25 Feb 2022 07:28:09 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 16A576182F for ; Fri, 25 Feb 2022 15:28:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1C0FCC340F0; Fri, 25 Feb 2022 15:28:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1645802888; bh=jk8FqDbw7B4cD1U1kMc0gy7Cew0kEKIWA7kyKmbSu0Q=; h=Subject:To:Cc:From:Date:From; b=FhM91dh34AfOPGNA+GTYjImoDI7RzhYX38Eg4Kqqx4UE0DIYjKI7O2o+dpNtaKs1O DHzWL3/anqp3yZBjV0Z1T9582YSG9shJLc3U+zoEFOMFrUfVAkiBOZU+2MXPXTB7Q0 2hbfwQlaiwcssezWETEDgpp3LRJSjw7CAbQfCrwM= Subject: FAILED: patch "[PATCH] bpf: Fix crash due to out of bounds access into reg2btf_ids." failed to apply to 5.15-stable tree To: memxor@gmail.com, ast@kernel.org Cc: From: Date: Fri, 25 Feb 2022 16:27:57 +0100 Message-ID: <1645802877214156@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 45ce4b4f9009102cd9f581196d480a59208690c1 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Thu, 17 Feb 2022 01:49:43 +0530 Subject: [PATCH] bpf: Fix crash due to out of bounds access into reg2btf_ids. When commit e6ac2450d6de ("bpf: Support bpf program calling kernel function") added kfunc support, it defined reg2btf_ids as a cheap way to translate the verifier reg type to the appropriate btf_vmlinux BTF ID, however commit c25b2ae13603 ("bpf: Replace PTR_TO_XXX_OR_NULL with PTR_TO_XXX | PTR_MAYBE_NULL") moved the __BPF_REG_TYPE_MAX from the last member of bpf_reg_type enum to after the base register types, and defined other variants using type flag composition. However, now, the direct usage of reg->type to index into reg2btf_ids may no longer fall into __BPF_REG_TYPE_MAX range, and hence lead to out of bounds access and kernel crash on dereference of bad pointer. Fixes: c25b2ae13603 ("bpf: Replace PTR_TO_XXX_OR_NULL with PTR_TO_XXX | PTR_MAYBE_NULL") Signed-off-by: Kumar Kartikeya Dwivedi Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20220216201943.624869-1-memxor@gmail.com diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index e16dafeb2450..3e23b3fa79ff 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -5688,7 +5688,8 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, } if (check_ptr_off_reg(env, reg, regno)) return -EINVAL; - } else if (is_kfunc && (reg->type == PTR_TO_BTF_ID || reg2btf_ids[reg->type])) { + } else if (is_kfunc && (reg->type == PTR_TO_BTF_ID || + (reg2btf_ids[base_type(reg->type)] && !type_flag(reg->type)))) { const struct btf_type *reg_ref_t; const struct btf *reg_btf; const char *reg_ref_tname; @@ -5706,7 +5707,7 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, reg_ref_id = reg->btf_id; } else { reg_btf = btf_vmlinux; - reg_ref_id = *reg2btf_ids[reg->type]; + reg_ref_id = *reg2btf_ids[base_type(reg->type)]; } reg_ref_t = btf_type_skip_modifiers(reg_btf, reg_ref_id,