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=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 5AB03C8300A for ; Thu, 30 Apr 2020 11:20:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 27BCB2076D for ; Thu, 30 Apr 2020 11:20:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Z+LJYXx3" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727079AbgD3LU4 (ORCPT ); Thu, 30 Apr 2020 07:20:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59418 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726819AbgD3LUz (ORCPT ); Thu, 30 Apr 2020 07:20:55 -0400 Received: from mail-pg1-x541.google.com (mail-pg1-x541.google.com [IPv6:2607:f8b0:4864:20::541]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9BD29C035494 for ; Thu, 30 Apr 2020 04:20:55 -0700 (PDT) Received: by mail-pg1-x541.google.com with SMTP id s18so2590650pgl.12 for ; Thu, 30 Apr 2020 04:20:55 -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; bh=06zPWEluu9vRkSomaV4Rb19WXIxUjIgbc58HvLTjqJU=; b=Z+LJYXx3rAp0alVaNJJBo3hQWwH0sS8uKeb5I1WLSBoiTNtojilGp+dLt03Kv55zcI q1lwkyWkVOqXWka3tCAKAXq8SaJeoubFtv7pGI7xNkuM+BGr2MrtaQIRZJvP+8PU2Gpr aX6eU65fXjIWDpQ2wa/FqNYYKQkpfPfn2C0ict2cHFr4gVlmKaY/+2yrYF/Ycr8nyY6e +WTaCJdvovAsALRr739OPLGmtQhglkKs7imDR8k/QEA9nZiQmXjpqpl4xuCJTrGj59+Z MWVpeE7juvbf7zYP6ng30dD9cIy7Q87GsTUKjGVLpORtQbFsaXK6XeOxPTZ9z0WArdew 643A== 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; bh=06zPWEluu9vRkSomaV4Rb19WXIxUjIgbc58HvLTjqJU=; b=Cr8TpGL5ozkSHcyiJn8Apv0xm/DEuI3AL9z8oGQJ/3/2w+/SG17qX6ZsMyfNaX9PSp sKdz3c0Np7of1b+l/B7xhyDgXd84sljT2kQ65iRTqgP38TYlFm6XhDZzt6R2q05Dc/fN DOZU4yBvRRwbV+jw4mdhSRChYUvVz6ZNePWKXJNAU4Ta8ldFAlqy0/BspxdgedGYHxVe Q6RlOww9QMifCmQtHbx8kz8cnmdieeWmTTt8PRfbyWmU1S+16dj8A37IRu3O7aUcayTW y+/xRz9g8+j//vIjWxQ2Ajw0akmBCO68OSSNcgBSiTih34AlEuuVzJWI8HM33FRsuAtz SpBQ== X-Gm-Message-State: AGi0PubP7blX/ZYmYHntxeLTAUSM+Vxp87oh0UE8dwn8ZsvaS+3+2+5X pQNO17oNU2Dox/zi8kaAnjU= X-Google-Smtp-Source: APiQypLiun5y7ugnBNE5XABMc7/XzmbIqAOoqAaEuiEAHodLIlhCyVblkPUYy9GeWNC1v8BNoEX80A== X-Received: by 2002:a62:3006:: with SMTP id w6mr2987066pfw.29.1588245655175; Thu, 30 Apr 2020 04:20:55 -0700 (PDT) Received: from ubuntu.localdomain ([220.116.27.194]) by smtp.gmail.com with ESMTPSA id q11sm3317108pfl.97.2020.04.30.04.20.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 30 Apr 2020 04:20:54 -0700 (PDT) From: youngjun To: Greg Kroah-Hartman Cc: Tejun Heo , linux-kernel@vger.kernel.org, youngjun Subject: [PATCH] fs: kernfs: fix possible null pointer dereferences Date: Thu, 30 Apr 2020 04:20:46 -0700 Message-Id: <20200430112046.53721-1-her0gyugyu@gmail.com> X-Mailer: git-send-email 2.17.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org kernfs_path_from_node_locked checks buf is NULL. But, two cases below are not covered. if(!kn_to) <--- case1 (buf can be NULL) return strlcpy(buf, "(null)", buflen); if(kn_from == kn_to) <--- case2 (buf can be NULL) return strlcpy(buf, "/", buflen); if (!buf) <--- checked here. return -EINVAL; buf NULL case needs to be checked first. Signed-off-by: youngjun --- fs/kernfs/dir.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c index 02fb5cc76e33..d802cfceddba 100644 --- a/fs/kernfs/dir.c +++ b/fs/kernfs/dir.c @@ -128,6 +128,9 @@ static int kernfs_path_from_node_locked(struct kernfs_node *kn_to, size_t depth_from, depth_to, len = 0; int i, j; + if (!buf) + return -EINVAL; + if (!kn_to) return strlcpy(buf, "(null)", buflen); @@ -137,9 +140,6 @@ static int kernfs_path_from_node_locked(struct kernfs_node *kn_to, if (kn_from == kn_to) return strlcpy(buf, "/", buflen); - if (!buf) - return -EINVAL; - common = kernfs_common_ancestor(kn_from, kn_to); if (WARN_ON(!common)) return -EINVAL; -- 2.17.1