From patchwork Tue Jul 14 00:38:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peilin Ye X-Patchwork-Id: 1328563 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=kXA12gfh; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4B5MDT01fkz9sRR for ; Tue, 14 Jul 2020 10:42:32 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726771AbgGNAmb (ORCPT ); Mon, 13 Jul 2020 20:42:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39626 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726257AbgGNAm3 (ORCPT ); Mon, 13 Jul 2020 20:42:29 -0400 Received: from mail-qv1-xf43.google.com (mail-qv1-xf43.google.com [IPv6:2607:f8b0:4864:20::f43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B7836C061755; Mon, 13 Jul 2020 17:42:29 -0700 (PDT) Received: by mail-qv1-xf43.google.com with SMTP id h18so6734726qvl.3; Mon, 13 Jul 2020 17:42:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=KdIW5He8ZiiCiJCefvMCxWAQ162LKqrQoM487o/uJO8=; b=kXA12gfh+GeMEU0kaSoQ15nqyvzVsppDR7KTdVpxyShQ4ztvA5r9mmzlEhnBgw6JM0 M00ZaD5scYu/PTcWMxJ3kv0hZ/2XO78OrGxpYpb3jhWXgfQbUTnqRwqFOIsDr+j2pAqZ VG8Q0fRmq8eJULv43+qfCdY9Ktf/a/hY4BI5P71MaaS572T0+rvdfB0qNBtmNLuYm/Ps fuCIymU+DnYkvMCpTVRVPkiC8b+NoUSPslqs22xgK65g6NPfK6UT4PlPNzCmCNNIhJnr Dsdm00orgJnSJy5lAamHKdi/YTHjKQI2HhK+As546ROmFhNnfbcMSCixrsSHP5yttjHH ibmQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=KdIW5He8ZiiCiJCefvMCxWAQ162LKqrQoM487o/uJO8=; b=bRiLL9P9PFWTnEP07ZSpy/3be42C+/glXZP6vbUvwhf976JQEVo1VW6AH8alr9Z0oX F2r/jOKb9+w6CPG3j1Ll7gbCRTbiTtnPkKu64oFPXD6tOb+blLxIh0LoiE52dIY9kBaA Ws3CT7WVlx8RaNIwWTGZVvG6dertr/BDDQxqk0Fcu6550Ja3CGcR5bil4gZ7ZQOTq7RK yPooX9l87/P60uJjnDR3rqrGIBT/EDiCPQ+7l/WcL59OR0quceYs+ssn0xNWfPVESNCY Hus/9eutG/2f6O5RstxqLFtZWbA+BWrwzxMvRwPZ8SiFdVcAH239hgxerq2YMsl/tpc8 rsNQ== X-Gm-Message-State: AOAM532C1SQEOCE5BFaxUNPSeXM9wl4vkHYZK3g9NNjjMNLlvokjJPX9 hNMwkuJQ3mErmdZdvJbyzQ== X-Google-Smtp-Source: ABdhPJwVjnzLFeP+i8s/I6t5APn4aBiJ18PZlMr//czA/GeBiS5dylC/raDPG+E1JxJrEBSrZxyUCw== X-Received: by 2002:a0c:8583:: with SMTP id o3mr2124679qva.108.1594687348930; Mon, 13 Jul 2020 17:42:28 -0700 (PDT) Received: from localhost.localdomain ([209.94.141.207]) by smtp.gmail.com with ESMTPSA id p36sm2849287qte.90.2020.07.13.17.42.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 13 Jul 2020 17:42:28 -0700 (PDT) From: Peilin Ye To: Alexei Starovoitov , Daniel Borkmann Cc: Peilin Ye , Martin KaFai Lau , Song Liu , Yonghong Song , Andrii Nakryiko , John Fastabend , KP Singh , Greg Kroah-Hartman , netdev@vger.kernel.org, bpf@vger.kernel.org, syzkaller-bugs@googlegroups.com, linux-kernel-mentees@lists.linuxfoundation.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com Subject: [Linux-kernel-mentees] [PATCH] bpf: Fix NULL pointer dereference in __btf_resolve_helper_id() Date: Mon, 13 Jul 2020 20:38:56 -0400 Message-Id: <20200714003856.194768-1-yepeilin.cs@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Prevent __btf_resolve_helper_id() from dereferencing `btf_vmlinux` as NULL. This patch fixes the following syzbot bug: https://syzkaller.appspot.com/bug?id=5edd146856fd513747c1992442732e5a0e9ba355 Reported-by: syzbot+ee09bda7017345f1fbe6@syzkaller.appspotmail.com Signed-off-by: Peilin Ye --- kernel/bpf/btf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 30721f2c2d10..3e981b183fa4 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -4088,7 +4088,7 @@ static int __btf_resolve_helper_id(struct bpf_verifier_log *log, void *fn, const char *tname, *sym; u32 btf_id, i; - if (IS_ERR(btf_vmlinux)) { + if (IS_ERR_OR_NULL(btf_vmlinux)) { bpf_log(log, "btf_vmlinux is malformed\n"); return -EINVAL; }