From patchwork Tue Jan 10 15:21:12 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chao Yu X-Patchwork-Id: 13095283 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 51760C46467 for ; Tue, 10 Jan 2023 15:22:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238932AbjAJPVv (ORCPT ); Tue, 10 Jan 2023 10:21:51 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58246 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238946AbjAJPVb (ORCPT ); Tue, 10 Jan 2023 10:21:31 -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 2CF3B87F21; Tue, 10 Jan 2023 07:21:30 -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 87B3D61762; Tue, 10 Jan 2023 15:21:29 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7C75EC433F1; Tue, 10 Jan 2023 15:21:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1673364089; bh=zl+JAJvLWEJRtU+N27yxQjit+w5i4sRPJ6RUeQgiYXM=; h=From:To:Cc:Subject:Date:From; b=TgNINrzmmiGy6ZCyjNr7NWQ9VaMZJGLQ9RfUH0k1t6wRZ2MVjAMYLGyLim8tYAE4T 7jv+39pqGsCLGAcNKBeS24que0muIp52QjbZMGnoTGS/BPRrFErve+H1XGxtG7dw6U ZnaQX2/zMPk1hhG64X3BqZfK3P55Gk3gtCzjWRCEN/tBMlkm2jzrJvmazCdJeq964J rJ0YIXM4qWMR4xh5kvMB4GlNE5ZrDCJNJR00kEWPJEuzZvG4IaR/z0Ds1WVCtAg/mU nWPjZWTzqx7OnUdLa7l8JCWMn/fRZeSs4GPz4COpRgOGUcvhgAKTzOsnXocmu8lXuw E5Vf8+cl1ue9g== From: Chao Yu To: akpm@linux-foundation.org, adobriyan@gmail.com Cc: viro@zeniv.linux.org.uk, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Chao Yu Subject: [PATCH] proc: fix to check name length in proc_lookup_de() Date: Tue, 10 Jan 2023 23:21:12 +0800 Message-Id: <20230110152112.1119517-1-chao@kernel.org> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org __proc_create() has limited dirent's max name length with 255, let's add this limitation in proc_lookup_de(), so that it can return -ENAMETOOLONG correctly instead of -ENOENT when stating a file which has out-of-range name length. Signed-off-by: Chao Yu --- fs/proc/generic.c | 5 ++++- fs/proc/internal.h | 3 +++ 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/fs/proc/generic.c b/fs/proc/generic.c index 587b91d9d998..5f52f20d5ed1 100644 --- a/fs/proc/generic.c +++ b/fs/proc/generic.c @@ -246,6 +246,9 @@ struct dentry *proc_lookup_de(struct inode *dir, struct dentry *dentry, { struct inode *inode; + if (dentry->d_name.len > PROC_NAME_LEN) + return ERR_PTR(-ENAMETOOLONG); + read_lock(&proc_subdir_lock); de = pde_subdir_find(de, dentry->d_name.name, dentry->d_name.len); if (de) { @@ -402,7 +405,7 @@ static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent, goto out; qstr.name = fn; qstr.len = strlen(fn); - if (qstr.len == 0 || qstr.len >= 256) { + if (qstr.len == 0 || qstr.len > PROC_NAME_LEN) { WARN(1, "name len %u\n", qstr.len); return NULL; } diff --git a/fs/proc/internal.h b/fs/proc/internal.h index b701d0207edf..7611bc684d9e 100644 --- a/fs/proc/internal.h +++ b/fs/proc/internal.h @@ -142,6 +142,9 @@ unsigned name_to_int(const struct qstr *qstr); /* Worst case buffer size needed for holding an integer. */ #define PROC_NUMBUF 13 +/* Max name length of procfs dirent */ +#define PROC_NAME_LEN 255 + /* * array.c */