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 X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BFDD7C4360C for ; Mon, 1 Mar 2021 18:03:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 90E0C653E9 for ; Mon, 1 Mar 2021 18:03:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239185AbhCASDa (ORCPT ); Mon, 1 Mar 2021 13:03:30 -0500 Received: from mail.kernel.org ([198.145.29.99]:52456 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232065AbhCAR4q (ORCPT ); Mon, 1 Mar 2021 12:56:46 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0872864F37; Mon, 1 Mar 2021 17:39:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1614620341; bh=CQDQaW6sR1J8//DimOziRTnwFc3cHOZkM+i1HTow/Ro=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aVlZEnVojZOcA43TpOpVbEQJJaktWynTQCCyYe+EF3/eeRRyytZ+caduySf8EUqpl eDpfLRbN8pqYoeZ4e13mZluPJCHZ2ksNBurv5tMh2CrpAsS29lgSD5+iGPXxPM2H5y SABrBT3JYOP52R059vC+ndVUcjBHkmZEhc3LZMmQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+580f4f2a272e452d55cb@syzkaller.appspotmail.com, Yonghong Song , Alexei Starovoitov , Sasha Levin Subject: [PATCH 5.11 119/775] bpf: Fix an unitialized value in bpf_iter Date: Mon, 1 Mar 2021 17:04:47 +0100 Message-Id: <20210301161207.557673427@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210301161201.679371205@linuxfoundation.org> References: <20210301161201.679371205@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Yonghong Song [ Upstream commit 17d8beda277a36203585943e70c7909b60775fd5 ] Commit 15d83c4d7cef ("bpf: Allow loading of a bpf_iter program") cached btf_id in struct bpf_iter_target_info so later on if it can be checked cheaply compared to checking registered names. syzbot found a bug that uninitialized value may occur to bpf_iter_target_info->btf_id. This is because we allocated bpf_iter_target_info structure with kmalloc and never initialized field btf_id afterwards. This uninitialized btf_id is typically compared to a u32 bpf program func proto btf_id, and the chance of being equal is extremely slim. This patch fixed the issue by using kzalloc which will also prevent future likely instances due to adding new fields. Fixes: 15d83c4d7cef ("bpf: Allow loading of a bpf_iter program") Reported-by: syzbot+580f4f2a272e452d55cb@syzkaller.appspotmail.com Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20210212005926.2875002-1-yhs@fb.com Signed-off-by: Sasha Levin --- kernel/bpf/bpf_iter.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/bpf/bpf_iter.c b/kernel/bpf/bpf_iter.c index 5454161407f1f..a0d9eade9c804 100644 --- a/kernel/bpf/bpf_iter.c +++ b/kernel/bpf/bpf_iter.c @@ -287,7 +287,7 @@ int bpf_iter_reg_target(const struct bpf_iter_reg *reg_info) { struct bpf_iter_target_info *tinfo; - tinfo = kmalloc(sizeof(*tinfo), GFP_KERNEL); + tinfo = kzalloc(sizeof(*tinfo), GFP_KERNEL); if (!tinfo) return -ENOMEM; -- 2.27.0