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=-9.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 69BDCC433DF for ; Sun, 14 Jun 2020 01:20:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 450162053B for ; Sun, 14 Jun 2020 01:20:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="UUWwANTZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726825AbgFNBUU (ORCPT ); Sat, 13 Jun 2020 21:20:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36048 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726803AbgFNBUU (ORCPT ); Sat, 13 Jun 2020 21:20:20 -0400 Received: from mail-qk1-x742.google.com (mail-qk1-x742.google.com [IPv6:2607:f8b0:4864:20::742]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BD785C03E96F; Sat, 13 Jun 2020 18:20:18 -0700 (PDT) Received: by mail-qk1-x742.google.com with SMTP id 205so12620801qkg.3; Sat, 13 Jun 2020 18:20:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:subject:date:message-id; bh=weNT1L1XKUjhZ/GyqfyR6sCkF+DRrUdSjJ2ej+SbbZw=; b=UUWwANTZUf9s6b09wIICLD5DT1wu6LnvZEZitokYHV2htO/B/xWJQS+FtpInW69ekG JVqvmJUXWH8Bw9o2+7Q4+FeK5o7+KsIHbkds4v2MsUTHpBkrE9fngOW2kMXrF18tOn8p NABJO8ZhMiWs2GCwhpu7If3MOXEYxXGJzQw6NvfhXMSlX5x0UUnOwzhy8IM+IwZDX4M1 3bY6aN3kwRnoDcQJq3gf5IeJws3uqAoa589vSlDcWcREZIhScvHocIKwKh0qcg2WtccV ILJHtHVRoCuqsthHNkSaU1YBcyAhkmqq1K/1Ru8AKyXKYh8B2xIFl3T2fMXj0872XHVe +vpg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id; bh=weNT1L1XKUjhZ/GyqfyR6sCkF+DRrUdSjJ2ej+SbbZw=; b=T5IeoVDOj/YJKXIKZQWEx4/umEqEr43dQNB9uLpLjto8ks1b1AUI13rphNTkBQiDwR hDiYvweFPjNaxPWwdNoaFtvm0kVLk2MmKpDjc91KeL+4G6gcpaxW0Ap3uX3bWkxPofUs IYm+AJ3Bn8jvcTDvCDtEwrTSXFbNRt1uHqjEOEFyCPmYjwfwyPXwHEvn2HvQUoElGUnD PxzL2jpKnOSVVzEATqj6ySKErzKF1gpecGuomOijhixGXMTWzOhYYdn+/+6j6w9I2UOS jWVjX/5ha5dz4XwQAhS2Ra9/zm0Z8H52KrCwNie0RU546B/Tlqd+/vtZZ80OlSRrNwnM WY2A== X-Gm-Message-State: AOAM532+kRhbq83agZQz5MQJbwOfatdEvpZAlT+AOtOGGBBuF3oXqgkM QUNoMdufF61fe3X971oAw0s= X-Google-Smtp-Source: ABdhPJxWbSwqsoRLmmhzpK3JmfQ7atmha/MGg4W9VIU4e/whsX6MJrO4pV4tEXhRaKT96K+BSIQMgQ== X-Received: by 2002:ae9:e8cc:: with SMTP id a195mr9819577qkg.408.1592097617772; Sat, 13 Jun 2020 18:20:17 -0700 (PDT) Received: from linux.home ([2604:2000:1344:41d:8024:443:2d4f:1b98]) by smtp.googlemail.com with ESMTPSA id 124sm7966356qkm.115.2020.06.13.18.20.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 13 Jun 2020 18:20:16 -0700 (PDT) From: Gaurav Singh To: gaurav1086@gmail.com, Jeff Dike , Richard Weinberger , Anton Ivanov , Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , Song Liu , Yonghong Song , Andrii Nakryiko , John Fastabend , KP Singh , Alex Dewar , =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , linux-um@lists.infradead.org (open list:USER-MODE LINUX (UML)), linux-kernel@vger.kernel.org (open list), netdev@vger.kernel.org (open list:BPF (Safe dynamic programs and tools)), bpf@vger.kernel.org (open list:BPF (Safe dynamic programs and tools)) Subject: [PATCH] Fix null pointer dereference in vector_user_bpf Date: Sat, 13 Jun 2020 21:19:40 -0400 Message-Id: <20200614012001.18468-1-gaurav1086@gmail.com> X-Mailer: git-send-email 2.17.1 Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org The bpf_prog is being checked for !NULL after uml_kmalloc but later its used directly for example: bpf_prog->filter = bpf and is also later returned upon success. Fix this, do a NULL check and return right away. Signed-off-by: Gaurav Singh --- arch/um/drivers/vector_user.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/um/drivers/vector_user.c b/arch/um/drivers/vector_user.c index c4a0f26b2824..0e6d6717bf73 100644 --- a/arch/um/drivers/vector_user.c +++ b/arch/um/drivers/vector_user.c @@ -789,10 +789,12 @@ void *uml_vector_user_bpf(char *filename) return false; } bpf_prog = uml_kmalloc(sizeof(struct sock_fprog), UM_GFP_KERNEL); - if (bpf_prog != NULL) { - bpf_prog->len = statbuf.st_size / sizeof(struct sock_filter); - bpf_prog->filter = NULL; + if (bpf_prog == NULL) { + printk(KERN_ERR "Failed to allocate bpf prog buffer"); + return NULL; } + bpf_prog->len = statbuf.st_size / sizeof(struct sock_filter); + bpf_prog->filter = NULL; ffd = os_open_file(filename, of_read(OPENFLAGS()), 0); if (ffd < 0) { printk(KERN_ERR "Error %d opening bpf file", -errno); -- 2.17.1